Topical Collection "COVID-19 Vaccines and Vaccination"

Editors

Prof. Dr. Ralph A. Tripp
E-Mail Website
Collection Editor
Department of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
Interests: viral immunology; vaccines; therapeutics; RSV; influenza; RNAi; miRNA
Special Issues, Collections and Topics in MDPI journals
Dr. Scott Anthony
E-Mail Website
Collection Editor
National Institute of Allergy and Infectious Diseases (NIAID), Frederick, MD, USA
Interests: the requirements for the generation and maintenance of resident memory CD8 T cells
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Associates,

There are >200 vaccine candidates for COVID-19 being developed. Of these, >50 candidate vaccines are in clinical trials. It is expected that the different vaccines in development will secure the chance that one or more will be efficacious and safe.

There are three approaches to vaccine design:

(1) whole virus,

(2) part of the virus that triggers immunity, or

(3) viral genetic material.

This Collection on “COVID-19 Vaccine Development and Vaccination” will highlight the recent effort to develop, test, and use vaccines on individuals with promising vaccine platforms against SARS-CoV-2. These approaches may include a whole virus approach (live-attenuated vaccine, inactivated vaccine, or viral vector vaccine), a subunit approach, or genetic approaches that include nucleic acid vaccines.

Prof. Dr. Ralph Tripp
Dr. Scott Anthony
Collection Editor,Editor in Chief

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Vaccines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (53 papers)

2022

Jump to: 2021

Article
Risk of Myocarditis and Pericarditis among Young Adults following mRNA COVID-19 Vaccinations
Vaccines 2022, 10(5), 722; https://doi.org/10.3390/vaccines10050722 - 05 May 2022
Viewed by 594
Abstract
There have been reports of cases of myocarditis and pericarditis as rare complications following mRNA COVID-19 vaccinations among young adults. While most reported cases are mild, this potential vaccine safety signal should be closely monitored. Using data from the CDC and the Vaccine [...] Read more.
There have been reports of cases of myocarditis and pericarditis as rare complications following mRNA COVID-19 vaccinations among young adults. While most reported cases are mild, this potential vaccine safety signal should be closely monitored. Using data from the CDC and the Vaccine Adverse Event Reporting System (VAERS), we calculated the combined reporting rate of myocarditis and pericarditis stratified by age group, sex, vaccine dose, and manufacturer, and compared these rates to the crude background incidence rates. Compared to the general population prior to the administration of the first COVID-19 vaccines in December 2020, we identified a higher-than-expected reporting rate of myocarditis and pericarditis following mRNA vaccination; the risk was higher after a second vaccine dose, higher in males than in females, and decreased with age. The highest risk was seen in males 12–17 years of age with approximately 6 cases per 100,000 second doses. Our findings suggest an increased risk of myocarditis and pericarditis in young males following a second dose of an mRNA COVID-19 vaccine. Since these findings are based on safety signals derived from passive surveillance data, confirmatory epidemiological studies should be undertaken. Full article
Article
Dermal Delivery of a SARS-CoV-2 Subunit Vaccine Induces Immunogenicity against Variants of Concern
Vaccines 2022, 10(4), 578; https://doi.org/10.3390/vaccines10040578 - 08 Apr 2022
Viewed by 753
Abstract
The ongoing coronavirus disease 2019 (COVID-19) pandemic continues to disrupt essential health services in 90 percent of countries today. The spike (S) protein found on the surface of the causative agent, the SARS-CoV-2 virus, has been the prime target for current vaccine research [...] Read more.
The ongoing coronavirus disease 2019 (COVID-19) pandemic continues to disrupt essential health services in 90 percent of countries today. The spike (S) protein found on the surface of the causative agent, the SARS-CoV-2 virus, has been the prime target for current vaccine research since antibodies directed against the S protein were found to neutralize the virus. However, as new variants emerge, mutations within the spike protein have given rise to potential immune evasion of the response generated by the current generation of SARS-CoV-2 vaccines. In this study, a modified, HexaPro S protein subunit vaccine, delivered using a needle-free high-density microarray patch (HD-MAP), was investigated for its immunogenicity and virus-neutralizing abilities. Mice given two doses of the vaccine candidate generated potent antibody responses capable of neutralizing the parental SARS-CoV-2 virus as well as the variants of concern, Alpha and Delta. These results demonstrate that this alternative vaccination strategy has the potential to mitigate the effect of emerging viral variants. Full article
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Article
An Association Study of HLA with the Kinetics of SARS-CoV-2 Spike Specific IgG Antibody Responses to BNT162b2 mRNA Vaccine
Vaccines 2022, 10(4), 563; https://doi.org/10.3390/vaccines10040563 - 05 Apr 2022
Cited by 1 | Viewed by 602
Abstract
BNT162b2, an mRNA-based SARS-CoV-2 vaccine (Pfizer-BioNTech, New York, NY, USA), is one of the most effective COVID-19 vaccines and has been approved by more than 130 countries worldwide. However, several studies have reported that the COVID-19 vaccine shows high interpersonal variability in terms [...] Read more.
BNT162b2, an mRNA-based SARS-CoV-2 vaccine (Pfizer-BioNTech, New York, NY, USA), is one of the most effective COVID-19 vaccines and has been approved by more than 130 countries worldwide. However, several studies have reported that the COVID-19 vaccine shows high interpersonal variability in terms of humoral and cellular responses, such as those with respect to SARS-CoV-2 spike protein immunoglobulin (Ig)G, IgA, IgM, neutralizing antibodies, and CD4+ and CD8+ T cells. The objective of this study is to investigate the kinetic changes in anti-SARS-CoV-2 spike IgG (IgG-S) profiles and adverse reactions and their associations with HLA profiles (HLA-A, -C, -B, -DRB1, -DQA1, -DQB1, -DPA1 and -DPB1) among 100 hospital workers from the Center Hospital of the National Center for Global Health and Medicine (NCGM), Tokyo, Japan. DQA1*03:03:01 (p = 0.017; Odd ratio (OR) 2.80, 95%confidence interval (CI) 1.05–7.25) was significantly associated with higher IgG-S production after two doses of BNT162b2, while DQB1*06:01:01:01 (p = 0.028, OR 0.27, 95%CI 0.05–0.94) was significantly associated with IgG-S declines after two doses of BNT162b2. No HLA alleles were significantly associated with either local symptoms or fever. However, C*12:02:02 (p = 0.058; OR 0.42, 95%CI 0.15–1.16), B*52:01:01 (p = 0.031; OR 0.38, 95%CI 0.14–1.03), DQA1*03:02:01 (p = 0.028; OR 0.39, 95%CI 0.15–1.00) and DPB1*02:01:02 (p = 0.024; OR 0.45, 95%CI 0.21–0.97) appeared significantly associated with protection against systemic symptoms after two doses of BNT162b2 vaccination. Further studies with larger sample sizes are clearly warranted to determine HLA allele associations with the production and long-term sustainability of IgG-S after COVID-19 vaccination. Full article
Article
Systemic Adverse Effects Induced by the BNT162b2 Vaccine Are Associated with Higher Antibody Titers from 3 to 6 Months after Vaccination
Vaccines 2022, 10(3), 451; https://doi.org/10.3390/vaccines10030451 - 15 Mar 2022
Viewed by 709
Abstract
Objective: We aimed to determine the relationship between vaccine-related adverse effects and antibody (Ab) titers from 3 to 6 months after the second dose of the BNT162b2 coronavirus disease 2019 (COVID-19) mRNA vaccine (Pfizer/BioNTech) in Japan. Methods: We enrolled 378 healthcare workers (255 [...] Read more.
Objective: We aimed to determine the relationship between vaccine-related adverse effects and antibody (Ab) titers from 3 to 6 months after the second dose of the BNT162b2 coronavirus disease 2019 (COVID-19) mRNA vaccine (Pfizer/BioNTech) in Japan. Methods: We enrolled 378 healthcare workers (255 women and 123 men) whose Ab titers were analyzed 3 and 6 months after the second dose in our previous study and whose characteristics and adverse effects were collected previously by using a structured self-report questionnaire. Results: The workers’ median age was 44 years. Although injection-site symptoms occurred with almost equal frequency between the first and second doses, systemic adverse effects, such as general fatigue and fever, were significantly more frequent after the second dose than after the first dose. Multivariate analysis showed that fever was significantly correlated with female participants for the second dose (odds ratio (OR), 2.139; 95% confidence interval (95% CI), 1.185–3.859), older age for the first dose (OR, 0.962; 95% CI, 0.931–0.994) and second dose (OR, 0.957; 95% CI, 0.936–0.979), and dyslipidemia for the first dose (OR, 8.750; 95% CI, 1.814–42.20). Age-adjusted Ab titers at 3 months after vaccination were 23.7% and 23.4% higher in patients with a fever than in those without a fever after the first and second dose, respectively. In addition, age-adjusted Ab titers at 3 and 6 months after the second dose were, respectively, 21.7% and 19.3% higher in the group in which an anti-inflammatory agent was used than in the group without the use of an anti-inflammatory agent. Conclusion: Participants with systemic adverse effects tend to have higher Ab titers from 3 to 6 months after the second dose of the BNT162b2 vaccine. Our results may encourage vaccination, even among people with vaccine hesitancy related to relatively common systemic adverse effects. Full article
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COVID-19 Breakthrough Infection after Inactivated Vaccine Induced Robust Antibody Responses and Cross-Neutralization of SARS-CoV-2 Variants, but Less Immunity against Omicron
Vaccines 2022, 10(3), 391; https://doi.org/10.3390/vaccines10030391 - 03 Mar 2022
Cited by 2 | Viewed by 607
Abstract
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and the waning of immunity in vaccinated individuals is resulting in increased numbers of SARS-CoV-2 breakthrough infections. This study investigated binding antibody responses and neutralizing activities against SARS-CoV-2 variants, in patients with [...] Read more.
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and the waning of immunity in vaccinated individuals is resulting in increased numbers of SARS-CoV-2 breakthrough infections. This study investigated binding antibody responses and neutralizing activities against SARS-CoV-2 variants, in patients with COVID-19 who had been fully vaccinated with CoronaVac (n = 77), individuals who had been fully vaccinated with CoronaVac but had not contracted COVID-19 (n = 170), and individuals who had received AZD1222 as a third vaccination (n = 210). Breakthrough infection was generally detected approximately 88 days after the second CoronaVac vaccination (interquartile range 68–100 days). Blood samples were collected at a median of 34 days after infection. Binding antibody levels in sera from patients with breakthrough infection were significantly higher than those in individuals who had received AZD1222 as a third vaccination. However, neutralizing activities against wild-type and variants, including alpha (B.1.1.7), beta (B.1.351), and delta (B.1.617.2), were comparable in patients with breakthrough infections and individuals who received a third vaccination with AZD1222, which exceeds 90%. Omicron (B.1.1.529) was neutralized less effectively by serum from breakthrough infection patients, with a 6.3-fold reduction compared to delta variants. The study suggests that breakthrough infection after two doses of an inactivated vaccine can induce neutralizing antibodies against omicron. Further investigation is needed to assess the long-term persistence of antibodies against the omicron variant. Full article
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Article
Reported Adverse Effects and Attitudes among Arab Populations Following COVID-19 Vaccination: A Large-Scale Multinational Study Implementing Machine Learning Tools in Predicting Post-Vaccination Adverse Effects Based on Predisposing Factors
Vaccines 2022, 10(3), 366; https://doi.org/10.3390/vaccines10030366 - 26 Feb 2022
Cited by 2 | Viewed by 1449
Abstract
Background: The unprecedented global spread of coronavirus disease 2019 (COVID-19) has imposed huge challenges on the healthcare facilities, and impacted every aspect of life. This has led to the development of several vaccines against COVID-19 within one year. This study aimed to assess [...] Read more.
Background: The unprecedented global spread of coronavirus disease 2019 (COVID-19) has imposed huge challenges on the healthcare facilities, and impacted every aspect of life. This has led to the development of several vaccines against COVID-19 within one year. This study aimed to assess the attitudes and the side effects among Arab communities after receiving a COVID-19 vaccine and use of machine learning (ML) tools to predict post-vaccination side effects based on predisposing factors. Methods: An online-based multinational survey was carried out via social media platforms from 14 June to 31 August 2021, targeting individuals who received at least one dose of a COVID-19 vaccine from 22 Arab countries. Descriptive statistics, correlation, and chi-square tests were used to analyze the data. Moreover, extensive ML tools were utilized to predict 30 post vaccination adverse effects and their severity based on 15 predisposing factors. The importance of distinct predisposing factors in predicting particular side effects was determined using global feature importance employing gradient boost as AutoML. Results: A total of 10,064 participants from 19 Arab countries were included in this study. Around 56% were female and 59% were aged from 20 to 39 years old. A high rate of vaccine hesitancy (51%) was reported among participants. Almost 88% of the participants were vaccinated with one of three COVID-19 vaccines, including Pfizer-BioNTech (52.8%), AstraZeneca (20.7%), and Sinopharm (14.2%). About 72% of participants experienced post-vaccination side effects. This study reports statistically significant associations (p < 0.01) between various predisposing factors and post-vaccinations side effects. In terms of predicting post-vaccination side effects, gradient boost, random forest, and XGBoost outperformed other ML methods. The most important predisposing factors for predicting certain side effects (i.e., tiredness, fever, headache, injection site pain and swelling, myalgia, and sleepiness and laziness) were revealed to be the number of doses, gender, type of vaccine, age, and hesitancy to receive a COVID-19 vaccine. Conclusions: The reported side effects following COVID-19 vaccination among Arab populations are usually non-life-threatening; flu-like symptoms and injection site pain. Certain predisposing factors have greater weight and importance as input data in predicting post-vaccination side effects. Based on the most significant input data, ML can also be used to predict these side effects; people with certain predicted side effects may require additional medical attention, or possibly hospitalization. Full article
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Evaluation of Simple Lateral Flow Immunoassays for Detection of SARS-CoV-2 Neutralizing Antibodies
Vaccines 2022, 10(3), 347; https://doi.org/10.3390/vaccines10030347 - 23 Feb 2022
Viewed by 523
Abstract
Immunization for the generation of protective antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged to be highly effective in preventing hospital admission, need for intensive care treatment and high mortality in the current SARS-CoV-2 pandemic. Lateral flow immune assays (LFIAs) [...] Read more.
Immunization for the generation of protective antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged to be highly effective in preventing hospital admission, need for intensive care treatment and high mortality in the current SARS-CoV-2 pandemic. Lateral flow immune assays (LFIAs) offer a simple and competitive option to monitor antibody production after vaccination. Here, we compared the diagnostic performance of three different lateral flow assays in detecting nucleocapsid protein (NP), S1 subunit (S1) and receptor binding domain (pseudo)-neutralizing antibodies (nRBD) in sera of 107 health care workers prior (V1), two weeks (V2) after first vaccination with BNT162b2 as well as three weeks (V3) and eight months later (V4). In sera at V1, overall specificity was >99%. At V3, LFIAs showed sensitivities between 98.1 and 100%. The comparison of S1 and nRBD LFIA with S1 ELISA and a focus reduction neutralization assay (FRNT) revealed high concordance at V3. Thus, the use of lateral flow immunoassays appears to have reasonable application in the short-term follow-up after vaccination for SARS-CoV-2. Full article
Article
Homologous and Heterologous Anti-COVID-19 Vaccination Does Not Induce New-Onset Formation of Autoantibodies Typically Accompanying Lupus Erythematodes, Rheumatoid Arthritis, Celiac Disease and Antiphospholipid Syndrome
Vaccines 2022, 10(2), 333; https://doi.org/10.3390/vaccines10020333 - 18 Feb 2022
Viewed by 1096
Abstract
The COVID-19 pandemics has caused the death of almost six million people worldwide. In order to establish collective immunity, the first vaccines that were approved in Germany were the vector virus-based vaccine Vaxzevria and the mRNA vaccines Comirnaty and Spikevax, respectively. As it [...] Read more.
The COVID-19 pandemics has caused the death of almost six million people worldwide. In order to establish collective immunity, the first vaccines that were approved in Germany were the vector virus-based vaccine Vaxzevria and the mRNA vaccines Comirnaty and Spikevax, respectively. As it was reported that SARS-CoV-2 can trigger autoimmunity, it is of significant interest to investigate whether COVID-19 vaccines evoke the formation of autoantibodies and subsequent autoimmunity. Here, we analyzed immune responses after different vaccination regimens (mRNA/mRNA, Vector/Vector or Vector/mRNA) with respect to anti-SARS-CoV-2-specific immunity and the development of autoantibodies well known for their appearance in distinct autoimmune diseases. We found that anti-SARS-CoV-2 antibody levels were 90% lower after Vector/Vector vaccination compared to the other vaccinations and that Vector/mRNA vaccination was more effective than mRNA/mRNA vaccination in terms of IgM and IgA responses. However, until 4 months after booster vaccination we only detected increases in autoantibodies in participants with already pre-existing autoantibodies whereas vaccinees showing no autoantibody formation before vaccination did not respond with sustained autoantibody production. Taken together, our study suggests that all used COVID-19 vaccines do not significantly foster the appearance of autoantibodies commonly associated with lupus erythematodes, rheumatoid arthritis, Celiac disease and antiphospholipid-syndrome but provide immunity to SARS-CoV-2. Full article
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Article
Propensity-Score-Matched Evaluation of Adverse Events Affecting Recovery after COVID-19 Vaccination: On Adenovirus and mRNA Vaccines
Vaccines 2022, 10(2), 284; https://doi.org/10.3390/vaccines10020284 - 13 Feb 2022
Viewed by 769
Abstract
This study aimed to observe adverse events following immunisation (AEFIs) that affected recovery within two weeks after COVID-19 vaccination and investigate their risks in propensity-score-matched populations. Data were collected from 447,346 reports from the VAERS between 1 January 2021 and 31 July 2021. [...] Read more.
This study aimed to observe adverse events following immunisation (AEFIs) that affected recovery within two weeks after COVID-19 vaccination and investigate their risks in propensity-score-matched populations. Data were collected from 447,346 reports from the VAERS between 1 January 2021 and 31 July 2021. Propensity-score-matched populations were constructed by adjusting for demographic characteristics and 11 underlying diseases in eligible subjects who received 1 of 3 COVID-19 vaccines: 19,462 Ad26.COV2.S, 120,580 mRNA-1273, and 100,752 BNT162b2. We observed that 88 suspected AEFIs (22 in Ad26.COV2.S, 62 in mRNA-1273, and 54 in BNT162b2) were associated with an increased risk of delayed recovery within 2 weeks after COVID-19 vaccinations. Nervous system, musculoskeletal and connective tissue, gastrointestinal, skin, and subcutaneous tissue disorders were the most common AEFIs after COVID-19 vaccination. Interestingly, four local and systemic reactions affected recovery in different vaccine recipients during our study period: asthenic conditions and febrile disorders in Ad26.COV2.S and mRNA-1273; general signs and symptoms in mRNA-1273 and BNT162b2; injection site reactions in Ad26.COV2.S and BNT162b2. Although it is necessary to confirm a causal relationship with COVID-19 vaccinations, some symptoms, including paralysis, allergic disorders, breathing abnormalities, and visual impairment, may hinder the recovery of these recipients. Full article
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Article
Antibody Response of Combination of BNT162b2 and CoronaVac Platforms of COVID-19 Vaccines against Omicron Variant
Vaccines 2022, 10(2), 160; https://doi.org/10.3390/vaccines10020160 - 21 Jan 2022
Cited by 7 | Viewed by 1649
Abstract
By vaccinating SARS-CoV-2 naïve individuals who have already received two doses of COVID-19 vaccines, we aimed to investigate whether a heterologous prime-boost strategy, using vaccines of different platforms as the booster dose, can enhance the immune response against SARS-CoV-2 virus variants. Participants were [...] Read more.
By vaccinating SARS-CoV-2 naïve individuals who have already received two doses of COVID-19 vaccines, we aimed to investigate whether a heterologous prime-boost strategy, using vaccines of different platforms as the booster dose, can enhance the immune response against SARS-CoV-2 virus variants. Participants were assigned into four groups, each receiving different combination of vaccinations: two doses of BNT162b2 followed by one dose of BNT162b2 booster (B-B-B); Combination of BNT162b2 (first dose) and CoronaVac (second dose) followed by one dose of BNT162b2 booster (B-C-B); two doses of CoronaVac followed by one dose of CoronaVac booster (C-C-C); two doses of CoronaVac followed by one dose of BNT162b2 booster (C-C-B). The neutralizing antibody in sera against the virus was determined with live virus microneutralization assay (vMN). The B-B-B group and C-C-B group demonstrated significantly higher immunogenicity against SARS-CoV-2 Wild type (WT), Beta variant (BV) and Delta variant (DV). In addition, the B-B-B group and C-C-B group showed reduced but existing protection against Omicron variant (OV). Moreover, A persistent rise in vMN titre against OV was observed 3 days after booster dose. Regarding safety, a heterologous prime-boost vaccine strategy is well tolerated. In this study, it was demonstrated that using vaccines of different platforms as booster dose can enhance protection against SARS-CoV-2 variants, offering potent neutralizing activity against wild-type virus (WT), Beta variant (BV), Delta variant (DV) and some protection against the Omicron variant (OV). In addition, a booster mRNA vaccine results in a more potent immune response than inactivated vaccine regardless of which platform was used for prime doses. Full article
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Article
The Safety and Immunogenicity of the BNT162b2 mRNA COVID-19 Vaccine in Japanese Patients after Allogeneic Stem Cell Transplantation
Vaccines 2022, 10(2), 158; https://doi.org/10.3390/vaccines10020158 - 21 Jan 2022
Viewed by 788
Abstract
Patients who have undergone hematopoietic stem cell transplantation (HSCT) for hematological disease experience high mortality when infected by coronavirus disease 2019 (COVID-19). However, the safety and efficacy of the COVID-19 vaccine in HSCT patients remain to be investigated. We prospectively evaluated the safety [...] Read more.
Patients who have undergone hematopoietic stem cell transplantation (HSCT) for hematological disease experience high mortality when infected by coronavirus disease 2019 (COVID-19). However, the safety and efficacy of the COVID-19 vaccine in HSCT patients remain to be investigated. We prospectively evaluated the safety and immunogenicity of the BNT162b2 mRNA COVID-19 vaccine (Pfizer BioNTech) in 25 Japanese allogeneic HSCT patients in comparison with 19 healthy volunteers. While anti-S1 antibody titers in almost all healthy volunteers after the second dose were higher than the cut-off value reported previously, levels in HSCT patients after the second dose were diverse. Nineteen patients (76%) had seroconversion of anti-S1 IgG. The median optical density of antibody levels in HSCT patients with low IgG levels (<600 mg/dL), steroid treatment, or low lymphocytes (<1000/μL) was significantly lower than that in the other HSCT patients. There were no serious adverse events (>Grade 3) and no new development or exacerbation of graft-versus-host disease after vaccination. We concluded that the BNT162b2 mRNA vaccine is safe and effective in Japanese allogeneic HSCT patients. Full article
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Article
The Association of Previous Vaccination with Live-Attenuated Varicella Zoster Vaccine and COVID-19 Positivity: An Israeli Population-Based Study
Vaccines 2022, 10(1), 74; https://doi.org/10.3390/vaccines10010074 - 04 Jan 2022
Cited by 1 | Viewed by 835
Abstract
The Bacillus Calmette–Guérin (BCG) vaccine affords indirect protection against COVID-19, which is presumably due to priming of the innate immune system. It was hypothesized that the live attenuated Varicella Zoster (LAVZ) vaccine, recommended for the elderly population, would also protect against COVID-19 infection. [...] Read more.
The Bacillus Calmette–Guérin (BCG) vaccine affords indirect protection against COVID-19, which is presumably due to priming of the innate immune system. It was hypothesized that the live attenuated Varicella Zoster (LAVZ) vaccine, recommended for the elderly population, would also protect against COVID-19 infection. A retrospective population-based cross-sectional study was conducted using the Leumit Health Services (LHS) database. LAVZ-vaccinated patients were matched with controls based on a propensity score model using 1:9 nearest-neighbor matching. Matching was based on age, gender, and the presence of some chronic disorders, which were selected according to their association with COVID-19 infection. Multivariate logistic regression analyses, adjusted for sex, age, smoking status, comorbidities, and chronic medications associated with COVID-19 risk, were used to estimate the association between LAVZ vaccination and COVID-19 RT-PCR results. Subjects (625) vaccinated with LAVZ and RT-PCR-tested for COVID-19 were identified. After 1:9 matching of subjects who received the LAVZ vaccine, 6250 subjects were included in the study. Multivariate logistic regression analysis demonstrated a significant and independent negative association between having received the LAVZ vaccine and the likelihood of COVID-19 infection (adjusted OR = 0.47 (95% CI 0.33–0.69, p < 0.001)). This association was further strengthened after separate analysis based on the time of LAVZ vaccination before COVID-19 RT-PCR testing. Individuals aged ≥50 years vaccinated with LAVZ had a decreased likelihood of being tested positive for COVID-19. Full article
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2021

Jump to: 2022

Article
Antibody Response of BNT162b2 and CoronaVac Platforms in Recovered Individuals Previously Infected by COVID-19 against SARS-CoV-2 Wild Type and Delta Variant
Vaccines 2021, 9(12), 1442; https://doi.org/10.3390/vaccines9121442 - 07 Dec 2021
Cited by 4 | Viewed by 1248
Abstract
Vaccinating recovered patients previously infected by COVID-19 with mRNA vaccines to boost their immune response against wild-type viruses (WT), we aimed to investigate whether vaccine platform and time of vaccination affect immunogenicity against the SARS-CoV-2 WT and Delta variant (DV). Convalescent patients infected [...] Read more.
Vaccinating recovered patients previously infected by COVID-19 with mRNA vaccines to boost their immune response against wild-type viruses (WT), we aimed to investigate whether vaccine platform and time of vaccination affect immunogenicity against the SARS-CoV-2 WT and Delta variant (DV). Convalescent patients infected by COVID-19 were recruited and received one booster dose of the BNT162b2 (PC-B) or CoronaVac (PC-C) vaccines, while SARS-CoV-2 naïve subjects received two doses of the BNT162b2 (CN-B) or CoronaVac (CN-C) vaccines. The neutralizing antibody in sera against the WT and DV was determined with live virus neutralization assay (vMN). The vMN geometric mean titre (GMT) against WT in recovered individuals previously infected by COVID-19 reduced significantly from 60.0 (95% confidence interval (CI), 46.5–77.4) to 33.9 (95% CI, 26.3–43.7) at 6 months post recovery. In the PC-B group, the BNT162b2 vaccine enhanced antibody response against WT and DV, with 22.3-fold and 20.4-fold increases, respectively. The PC-C group also showed 1.8-fold and 2.2-fold increases for WT and DV, respectively, after receiving the CoronaVac vaccine. There was a 10.6-fold increase in GMT in the CN-B group and a 1.3-fold increase in the CN-C group against DV after full vaccination. In both the PC-B and PC-C groups, there was no difference between GMT against WT and DV after vaccination. Subjects in the CN-B and CN-C groups showed inferior GMT against DV compared with GMT against WT after vaccination. In this study, one booster shot effectively enhanced the pre-existing neutralizing activity against WT and DV in recovered subjects. Full article
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Article
Unfolding the Mild to Moderate Short-Term Side Effects of Four COVID-19 Vaccines Used in Bahrain: A Cross-Sectional Study
Vaccines 2021, 9(11), 1369; https://doi.org/10.3390/vaccines9111369 - 22 Nov 2021
Cited by 2 | Viewed by 1007
Abstract
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) created a global pandemic (COVID-19) that has resulted in massive health and economic losses. The current unavailability of treatments leaves vaccination as the only way to control this disease. There are four vaccines (Sinopharm, Pfizer—BioNTech, Sputnik, [...] Read more.
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) created a global pandemic (COVID-19) that has resulted in massive health and economic losses. The current unavailability of treatments leaves vaccination as the only way to control this disease. There are four vaccines (Sinopharm, Pfizer—BioNTech, Sputnik, and AstraZeneca) available in Bahrain. This project aimed to study the most common side effects resulting from the first and second doses of these four vaccines. Data were collected through an online questionnaire answered by 311 individuals who received both doses of one of these four vaccines. The results of this study revealed that regardless of the vaccine identity, participants experienced more side effects from the second dose. Among the different side effects, pain at the site of injection was primarily observed after the first dose of the Pfizer vaccine (43%), which was followed by the AstraZeneca vaccine (31%). Moreover, fever was observed in participants after the first dose of the Sputnik vaccine (37%), while headache was mainly observed after the first dose of the Pfizer vaccine (32%). It is important to note that fatigue was observed after the first dose of all four vaccines but was reported by the highest proportion of respondents in the Pfizer group (28%). Interestingly, there are some side effects, such as pain at the site of injection, that are correlated with fever (r = 0.909). Similarly, headache is correlated with fever (r = 0.801) and pain at the site of injection (r = 0.868). Overall, it was observed that recipients of the Sinopharm vaccine reported the mildest side effects among all four vaccines. The crucial finding of this study is that the first and second dosage post-vaccination side effects were modest and predictable with no occurrences of hospitalization; this information can assist in lessening vaccine apprehension. Full article
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Article
COVID-19 Vaccine Boosters: The Good, the Bad, and the Ugly
Vaccines 2021, 9(11), 1299; https://doi.org/10.3390/vaccines9111299 - 09 Nov 2021
Cited by 15 | Viewed by 4843
Abstract
Pursuing vaccinations against COVID-19 brings hope to limit the spread of SARS-CoV-2 and remains the most rational decision under pandemic conditions. However, it does not come without challenges, including temporary shortages in vaccine doses, significant vaccine inequity, and questions regarding the durability of [...] Read more.
Pursuing vaccinations against COVID-19 brings hope to limit the spread of SARS-CoV-2 and remains the most rational decision under pandemic conditions. However, it does not come without challenges, including temporary shortages in vaccine doses, significant vaccine inequity, and questions regarding the durability of vaccine-induced immunity that remain unanswered. Moreover, SARS-CoV-2 has undergone evolution with the emergence of its novel variants, characterized by enhanced transmissibility and ability to at least partially evade neutralizing antibodies. At the same time, serum antibody levels start to wane within a few months after vaccination, ultimately increasing the risk of breakthrough infections. This article discusses whether the administration of booster doses of COVID-19 vaccines is urgently needed to control the pandemic. We conclude that, at present, optimizing the immunity level of wealthy populations cannot come at the expense of low-income regions that suffer from vaccine unavailability. Although the efficiency of vaccination in protecting from infection may decrease over time, current data show that efficacy against severe disease, hospitalization, and death remains at a high level. If vaccine coverage continues at extremely low levels in various regions, including African countries, SARS-CoV-2 may sooner or later evolve into variants better adapted to evade natural and vaccine-induced immunity, ultimately bringing a global threat that, of course, includes wealthy populations. We offer key recommendations to increase vaccination rates in low-income countries. The pandemic is, by definition, a major epidemiological event and requires looking beyond one’s immediate self-interest; otherwise, efforts to contain it will be futile. Full article
Article
Humoral Response after Vaccination with Half-Dose of BNT162b2 in Subjects under 55 Years of Age
Vaccines 2021, 9(11), 1277; https://doi.org/10.3390/vaccines9111277 - 04 Nov 2021
Cited by 1 | Viewed by 1601
Abstract
In the context of the ongoing COVID-19 pandemic, using a half-dose schedule vaccination can help to return to normalcy in a cost-efficient manner, which is especially important for low and middle-income countries. We undertook a study to confirm that in adults up to [...] Read more.
In the context of the ongoing COVID-19 pandemic, using a half-dose schedule vaccination can help to return to normalcy in a cost-efficient manner, which is especially important for low and middle-income countries. We undertook a study to confirm that in adults up to 55 years old, the humoral response to the half-dose (15 µg, 35 participants between 18 and 55 years old) and to the recommended dose (30 µg, 155 participants) in the two-dose three-week interval schedule would be comparable. Antibody levels were measured by the Elecsys Anti-SARS-CoV-2 S assay (Roche Diagnostics, upper detection limit: 2570 BAU/mL) on the day of dose 2 of the vaccine and then 8–10 days later to assess peak response to dose 2. The difference in proportions between the participants who did and did not exceed the upper detection limit 8–10 days after dose 2 was not statistically significant (p = 0.152). We suggest that a half-dose schedule can help to achieve widespread vaccination coverage more quickly and cheaply. Full article
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Communication
Assessment of Anti-SARS-CoV-2 Antibodies Post-Coronavac Vaccination in the Amazon Region of Brazil
Vaccines 2021, 9(10), 1169; https://doi.org/10.3390/vaccines9101169 - 12 Oct 2021
Cited by 3 | Viewed by 846
Abstract
The present study evaluated the frequency of seropositivity for anti-SARS-CoV-2 (S1 and S2) total antibodies and anti-SARS-CoV-2 (receptor binding domain-RBD-S1) neutralizing antibodies in individuals vaccinated with the immunizing agent Coronavac. This was a cross-sectional study involving 358 individuals divided into two groups. Group [...] Read more.
The present study evaluated the frequency of seropositivity for anti-SARS-CoV-2 (S1 and S2) total antibodies and anti-SARS-CoV-2 (receptor binding domain-RBD-S1) neutralizing antibodies in individuals vaccinated with the immunizing agent Coronavac. This was a cross-sectional study involving 358 individuals divided into two groups. Group 1 consisted of 205 volunteers who were tested for anti-SARS-CoV-2 total antibodies; group 2 consisted of 153 individuals tested for the presence of anti-SARS-CoV-2 neutralizing antibodies. Seropositivity was greater than 70% in both groups, although 17.6% and 20.9% of individuals showed no neutralizing or total antibody reactivity, respectively. The frequency of anti-SARS-CoV-2 total antibodies displayed a significantly different distribution between the sexes but not according to age. The frequency of anti-SARS-CoV-2 neutralizing antibodies was 93.3% (95% CI 68.1–99.8) in the age group from 21 to 40 years but significantly decreased with advancing age, and was 76.2% (95% CI 52.8–91.8) for 41 to 60 years, 72.5% (95% CI 62.8–80.9) for 61 to 80 years, and 46.7% (95% CI 21.3–73.4) for >80 years. Our results reveal a high prevalence of anti-SARS-CoV-2 total antibodies and anti-SARS-CoV-2 neutralizing antibodies in individuals who received both doses of the Coronavac vaccine, suggesting a lower effectiveness of the humoral immune response among those older than 60 years of age, which might be associated with senescence of the immune system. Full article
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Article
Immunological Response to COVID-19 Vaccination in Ovarian Cancer Patients Receiving PARP Inhibitors
Vaccines 2021, 9(10), 1148; https://doi.org/10.3390/vaccines9101148 - 08 Oct 2021
Cited by 2 | Viewed by 1598
Abstract
Objective: Vaccination for SARS-CoV-2 provides significant protection against the infection in the general population. However, limited data exist for cancer patients under systemic therapy. Methods: In this cohort, we prospectively enrolled cancer patients treated with PARPi as well as healthy volunteers in order [...] Read more.
Objective: Vaccination for SARS-CoV-2 provides significant protection against the infection in the general population. However, limited data exist for cancer patients under systemic therapy. Methods: In this cohort, we prospectively enrolled cancer patients treated with PARPi as well as healthy volunteers in order to study the kinetics of anti-SARS-CoV-2 antibodies (NAbs) after COVID-19 vaccination. Baseline demographics, co-morbidities, and NAb levels were compared between the two groups. Results: The results of the cohort of 36 patients receiving PARP inhibitors are presented here. Despite no new safety issues being noticed, their levels of SARS-CoV-2 neutralizing antibodies were significantly lower in comparison to matched healthy volunteers up to day 30 after the second dose. Conclusions: These results suggest that maintaining precautions against COVID-19 is essential for cancer patients and should be taken into consideration for the patients under treatment, while further exploration is needed to reduce the uncertainty of SARS-CoV-2 immunity among cancer patients under treatment. Full article
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Article
Weak Cross-Lineage Neutralization by Anti SARS-CoV-2 Spike Antibodies after Natural Infection or Vaccination Is Rescued by Repeated Immunological Stimulation
Vaccines 2021, 9(10), 1124; https://doi.org/10.3390/vaccines9101124 - 02 Oct 2021
Cited by 1 | Viewed by 1175
Abstract
After over one year of evolution, through billions of infections in humans, SARS-CoV-2 has evolved into a score of slightly divergent lineages. A few different amino acids in the spike proteins of these lineages can hamper both natural immunity against reinfection, and vaccine [...] Read more.
After over one year of evolution, through billions of infections in humans, SARS-CoV-2 has evolved into a score of slightly divergent lineages. A few different amino acids in the spike proteins of these lineages can hamper both natural immunity against reinfection, and vaccine efficacy. In this study, the in vitro neutralizing potency of sera from convalescent COVID-19 patients and vaccinated subjects was analyzed against six different SARS-CoV-2 lineages, including the latest B.1.617.2 (or Delta variant), in order to assess the cross-neutralization by anti-spike antibodies. After both single dose vaccination, or natural infection, the neutralizing activity was low and fully effective only against the original lineage, while a double dose or a single dose of vaccine, even one year after natural infection, boosted the cross-neutralizing activity against different lineages. Neither binding, nor the neutralizing activity of sera after vaccination, could predict vaccine failure, underlining the need for additional immunological markers. This study points at the importance of the anamnestic response and repeated vaccine stimulations to elicit a reasonable cross-lineage neutralizing antibody response. Full article
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Article
Neutralizing Antibodies against SARS-CoV-2, Anti-Ad5 Antibodies, and Reactogenicity in Response to Ad5-nCoV (CanSino Biologics) Vaccine in Individuals with and without Prior SARS-CoV-2
Vaccines 2021, 9(9), 1047; https://doi.org/10.3390/vaccines9091047 - 20 Sep 2021
Cited by 8 | Viewed by 3241
Abstract
This is the first study outside of clinical trials (phase I–III) evaluating the ability of the Ad5-nCoV vaccine to generate neutralizing antibodies and the factors associated with optimal or suboptimal response. In a longitudinal assay, 346 people (117 with prior COVID-19 and 229 [...] Read more.
This is the first study outside of clinical trials (phase I–III) evaluating the ability of the Ad5-nCoV vaccine to generate neutralizing antibodies and the factors associated with optimal or suboptimal response. In a longitudinal assay, 346 people (117 with prior COVID-19 and 229 without prior COVID-19) vaccinated with Ad5-nCoV were recruited. The percentage of neutralizing antibodies against SARS-CoV-2 (Surrogate Virus Neutralization Test) and antibodies against Ad5 (ADV-Ad5 IgG ELISA) were quantified pre and post-vaccination effects. The Ad5-nCoV vaccine induces higher neutralizing antibodies percentage in individuals with prior COVID-19 than those without prior COVID-19 (median [IQR]: 98% [97–98.1] vs. 72% [54–90], respectively; p < 0.0001). Furthermore, a natural infection (before vaccination) induces more neutralizing antibodies percentage than immunized individuals without prior COVID-19 (p < 0.01). No patient had vaccine-severe adverse effects. The age, antidepressant, and immunosuppressive treatments, reactogenicity, and history of COVID-19 are associated with impaired antibody production. The anti-Ad5 antibodies increased after 21 days of post-vaccination in all groups (p < 0.01). We recommend the application of a booster dose of Ad5-nCoV, especially for those individuals without previous COVID-19 infection. Finally, the induction of anti-Ad5 antibodies after vaccination should be considered if a booster with the same vaccine is planned. Full article
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Article
Immunological Analysis of People in Northeast China after SARS-CoV-2 Inactivated Vaccine Injection
Vaccines 2021, 9(9), 1028; https://doi.org/10.3390/vaccines9091028 - 16 Sep 2021
Cited by 4 | Viewed by 985
Abstract
Clarifying changes in the immune microenvironment caused by vaccination is crucial for the development and application of vaccines. In this study, we analyzed seroconversion of antibodies, 12 key cytokines, and 34 lymphocyte subsets at three time points (D-1, D14, and D42) around vaccination [...] Read more.
Clarifying changes in the immune microenvironment caused by vaccination is crucial for the development and application of vaccines. In this study, we analyzed seroconversion of antibodies, 12 key cytokines, and 34 lymphocyte subsets at three time points (D-1, D14, and D42) around vaccination and differences between two inactivated vaccines (Sinopharm and Sinovas) to understand the immune response induced by inactivated vaccines in the real world. The results showed that 62.5% and 75% of the participants achieved neutralizing antibody seroconversion on D14 and D42, respectively. After vaccination, IL-5 and IL-6 increased, and INF-γ decreased. IL6, IL-1B, INF-γ, IL-8, and IL-12p70 showed statistical significance in the comparison of different groups. In terms of lymphocyte subsets, CD3 +, CD56 +, CD3 + CD8 +, CD8 + CD71 +, and CD56 + CD71 + showed upward trend, while CD19 +, CD4 + CD8 +, CD8 + CD45RA +, CD4 + HLA-DR +, CD8 + HLA-DR +, and CD8 + CD38 + showed downward trend. Additionally, we found certain differences between the two vaccines in neutralizing antibodies, cytokines, and lymphocyte subsets. This research is a clinical observation on the immune response after vaccination through detecting various immune indicators, which showed that the inactivated vaccines induced both humoral immunity by producing neutralizing antibodies and cellular immunity. The cellular immunity induced by these two vaccines was a Th2-biased response, and it may also lead to a mild Th1-type response. Full article
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Brief Report
Increased Risk of Urticaria/Angioedema after BNT162b2 mRNA COVID-19 Vaccine in Health Care Workers Taking ACE Inhibitors
Vaccines 2021, 9(9), 1011; https://doi.org/10.3390/vaccines9091011 - 11 Sep 2021
Cited by 4 | Viewed by 1671
Abstract
Urticarial eruptions and angioedema are the most common cutaneous reactions in patients undergoing mRNA COVID-19 vaccinations. The vasoactive peptide bradykinin has long been known to be involved in angioedema and recently also in urticaria. Bradykinin is mainly catabolized by angiotensin-converting enzyme (ACE), which [...] Read more.
Urticarial eruptions and angioedema are the most common cutaneous reactions in patients undergoing mRNA COVID-19 vaccinations. The vasoactive peptide bradykinin has long been known to be involved in angioedema and recently also in urticaria. Bradykinin is mainly catabolized by angiotensin-converting enzyme (ACE), which is inhibited by ACE inhibitors, a commonly employed class of antihypertensive drugs. We evaluated the risk of developing urticaria/angioedema after inoculation with the BNT162b2 mRNA COVID-19 vaccine in a population of 3586 health care workers. The influences of ACE inhibitors and selected potential confounding variables (sex, age, previous SARS-CoV-2 infection, and allergy history) were evaluated by fitting univariate and multivariable Poisson regression models. The overall cumulative incidence of urticaria/angioedema was 1.8% (65 out of 3586; 95% CI: 1.4–2.3%). Symptoms were mild, and no subject consulted a physician. Subjects taking ACE inhibitors had an adjusted three-fold increased risk of urticaria/angioedema (RR 2.98, 95% CI: 1.12–7.96). When we restricted the analysis to those aged 50 years or more, the adjusted RR was 3.98 (95% CI: 1.44–11.0). In conclusion, our data indicate that subjects taking ACE inhibitors have an increased risk of urticaria/angioedema after vaccination with the BNT162b2 mRNA COVID-19 vaccine. Symptoms are mild and self-limited; however, they should be considered to adequately advise subjects undergoing vaccination. Full article
Case Report
Intradermal ChAdOx1 Vaccine Following Two CoronaVac Shots: A Case Report
Vaccines 2021, 9(9), 990; https://doi.org/10.3390/vaccines9090990 - 04 Sep 2021
Cited by 3 | Viewed by 3865
Abstract
Inactivated SARS-CoV-2 vaccines are used in many countries with uncertain immunogenicity. Intradermal ChAdOx1 has been proposed as a resource-efficient heterologous third booster shot. A 52-year-old healthy male healthcare professional had received two intramuscular CoronaVac shots on 21 April and 23 May 2021, and [...] Read more.
Inactivated SARS-CoV-2 vaccines are used in many countries with uncertain immunogenicity. Intradermal ChAdOx1 has been proposed as a resource-efficient heterologous third booster shot. A 52-year-old healthy male healthcare professional had received two intramuscular CoronaVac shots on 21 April and 23 May 2021, and volunteered to take a 0.1 mL ChAdOx1 vaccine intradermally on 29 June 2021, with minimal local reactions. The declining IgG levels against spike protein from the two CoronaVac shots increased to higher than 10,000 AU/mL two weeks after the intradermal ChAdOx1. Moreover, the neutralizing antibody increased from 66.77% to almost 100%. A ratio of 6.6:9.7 of IgA:IgG was observed. The 50% pseudovirus neutralization titer (PVNT50) against lentiviral pseudovirus bearing a codon-optimized spike gene (wild type, alpha, beta, and delta) were 1812.42, 822.99, 1025.42, 1347.13, respectively. The SARS-CoV-2-specific T cells to spike protein–peptide pools (532–788 SFU/106 PBMCs) were detected. In conclusion, the antibody and cellular responses to the intradermal ChAdOx1, as a third booster dose in a healthy volunteer who received two intramuscular CoronaVac shots, revealed a dramatic increase in the total antibodies, including IgG, IgA, as well as T cell responses against spike protein. The immune response from intradermal ChAdOx1 should be further investigated in a larger population. Full article
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Review
Safety and Efficacy of COVID-19 Vaccines: A Systematic Review and Meta-Analysis of Different Vaccines at Phase 3
Vaccines 2021, 9(9), 989; https://doi.org/10.3390/vaccines9090989 - 04 Sep 2021
Cited by 14 | Viewed by 4447
Abstract
This systematic review and meta-analysis was conducted to compare the safety and efficacy of 2019 novel coronavirus disease (COVID-19) vaccines according to vaccine platform and severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection severity. Articles published between 24 January 2020 and 30 May [...] Read more.
This systematic review and meta-analysis was conducted to compare the safety and efficacy of 2019 novel coronavirus disease (COVID-19) vaccines according to vaccine platform and severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection severity. Articles published between 24 January 2020 and 30 May 2021 were retrieved via a PubMed and EMBASE search. A total of 12 reports on phase-3 clinical trials and observational studies of COVID-19 vaccines were included in the review. In terms of vaccine safety, mRNA vaccines showed more relevance to serious adverse events than viral vector and inactivated vaccines, but no solid evidence indicated that COVID-19 vaccines directly caused serious adverse events. Serious metabolic, musculoskeletal, immune-system, and renal disorders were more common among inactivated vaccine recipients, and serious gastrointestinal complications and infections were more common among viral vector and inactivated vaccine recipients. The occurrence of serious vessel disorders was more frequent in mRNA vaccines. In terms of efficacy, two mRNA vaccine doses conferred a lesser risk of SARS-COV-2 infection (odds ratio: 0.05; 95% confidence interval: 0.02–0.13) than did vaccination with viral vector and inactivated vaccines. All vaccines protected more against symptomatic than asymptomatic cases (risk ratio, 0.11 vs. 0.34), but reduced the risk of severe SARS-COV-2 infection. The COVID-19 vaccines assessed in this study are sufficiently safe and effective. The results indicate that two mRNA vaccine doses prevent SARS-COV-2 infection most effectively, but further research is needed due to the high degree of heterogeneity among studies in this sample. Interventions should be implemented continuously to reduce the risks of infection after one vaccine dose and asymptomatic infection. Full article
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Article
COVID-19 Subunit Vaccine with a Combination of TLR1/2 and TLR3 Agonists Induces Robust and Protective Immunity
Vaccines 2021, 9(9), 957; https://doi.org/10.3390/vaccines9090957 - 27 Aug 2021
Cited by 4 | Viewed by 1234
Abstract
The development of COVID-19 vaccines is critical in controlling global health issues under the COVID-19 pandemic. The subunit vaccines are the safest and most widely used vaccine platform and highly effective against a multitude of infectious diseases. An adjuvant is essential for subunit [...] Read more.
The development of COVID-19 vaccines is critical in controlling global health issues under the COVID-19 pandemic. The subunit vaccines are the safest and most widely used vaccine platform and highly effective against a multitude of infectious diseases. An adjuvant is essential for subunit vaccines to enhance the magnitude and durability of immune responses. In this study, we determined whether a combination of toll-like receptor (TLR)1/2 and TLR3 agonists (L-pampo) can be a potent adjuvant for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subunit vaccine. We measured a neutralizing antibody (nAb) and an angiotensin-converting enzyme 2 (ACE2) receptor-blocking antibody against SARS-CoV-2 receptor-binding domain (RBD). We also detected interferon-gamma (IFN-γ) production by using ELISPOT and ELISA assays. By employing a ferret model, we detected nAbs and IFN-γ producing cells and measured viral load in nasal wash after the challenge of SARS-CoV-2. We found that SARS-CoV-2 antigens with L-pampo stimulated robust humoral and cellular immune responses. The efficacy of L-pampo was higher than the other adjuvants. Furthermore, in the ferret model, SARS-CoV-2 antigens with L-pampo elicited nAb response and antigen-specific cellular immune response against SARS-CoV-2, resulting in substantially decreased viral load in their nasal wash. Our study suggests that SARS-CoV-2 antigens formulated with TLR agonists, L-pampo, can be a potent subunit vaccine to promote sufficient protective immunity against SARS-CoV-2. Full article
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Brief Report
Rhabdomyolysis Following Ad26.COV2.S COVID-19 Vaccination
Vaccines 2021, 9(9), 956; https://doi.org/10.3390/vaccines9090956 - 27 Aug 2021
Cited by 5 | Viewed by 1304
Abstract
We report the case of a 19-year-old male who complained of myalgia, muscle weakness, and darkened urine two days after receiving his Ad26.COV2.S (Johnson & Johnson, New Brunswick, New Jersey, United States) COVID-19 vaccination. Blood examination revealed an increased creatine kinase (CK) level, [...] Read more.
We report the case of a 19-year-old male who complained of myalgia, muscle weakness, and darkened urine two days after receiving his Ad26.COV2.S (Johnson & Johnson, New Brunswick, New Jersey, United States) COVID-19 vaccination. Blood examination revealed an increased creatine kinase (CK) level, and his urinary dipstick tested positive for blood, indicative of acute rhabdomyolysis. Serum creatinine levels were normal. Rhabdomyolysis due to strenuous physical activity was ruled out and further diagnostics excluded an autoimmune cause. Under repeated treatment with intravenous fluid resuscitation (outpatient treatment), his symptoms resolved and peak CK levels of 44,180 U/L returned to almost normal levels within two weeks. Rhabdomyolysis is a rare, potentially fatal vaccine-induced reaction. Further research is needed to better understand the underlying pathomechanism and to investigate whether subcutaneous injection of vaccines may be able to prevent rhabdomyolysis. Full article
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Article
Persistence of Anti-S Titre among Healthcare Workers Vaccinated with BNT162b2 mRNA COVID-19
Vaccines 2021, 9(9), 947; https://doi.org/10.3390/vaccines9090947 - 25 Aug 2021
Cited by 6 | Viewed by 1460
Abstract
The COVID-19 pandemic has led to health, social and economic consequences for public health systems. As a result, the development of safe and effective vaccines, in order to contain the infection quickly became a priority. The first vaccine approved by the Italian Agency [...] Read more.
The COVID-19 pandemic has led to health, social and economic consequences for public health systems. As a result, the development of safe and effective vaccines, in order to contain the infection quickly became a priority. The first vaccine approved by the Italian Agency for Drugs Authorization (AIFA) was the BNT162b2 mRNA vaccine, developed by BioNTech and Pfizer (Comirnaty). Comirnaty contains a molecule called messenger RNA (mRNA), which is a nucleoside-modified RNA that encodes the SARS-CoV-2 spike glycoprotein. Even if data from phase I suggest that vaccine induced antibodies can persist for up to six months following the second shot of BNT vaccine, data regarding the real duration of immunological protection are lacking. In this study, we aimed to evaluate the duration of serological protection by detecting the presence of anti-S-RBD (receptor-binding domain) antibodies for SARS-CoV-2 among a large group of healthcare workers (HCWs) three months after vaccination. 99% of HCWs had a detectable titre of anti-S SARS-CoV-2 antibodies 90 days after the second vaccine shot. Elderly operators showed significantly lower levels of protective antibodies when compared to the younger ones, thus they could become unprotected earlier than other operators. Full article
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Article
Predictors of COVID-19 Vaccine Intention among the Saudi Arabian Population: A Cross-Sectional Survey
Vaccines 2021, 9(8), 892; https://doi.org/10.3390/vaccines9080892 - 12 Aug 2021
Cited by 3 | Viewed by 1384
Abstract
The long-term solution to managing the current COVID-19 pandemic is through mass immunization of the population. However, uncertainty or unwillingness to receive the vaccine could be a barrier in attaining sufficient vaccine coverage. Therefore, understanding the psychology of the population towards the vaccines [...] Read more.
The long-term solution to managing the current COVID-19 pandemic is through mass immunization of the population. However, uncertainty or unwillingness to receive the vaccine could be a barrier in attaining sufficient vaccine coverage. Therefore, understanding the psychology of the population towards the vaccines against COVID-19 is of paramount importance. Our study was aimed at determining the predictors of COVID-19 vaccine intention in the Saudi Arabian population. A structured questionnaire guided by the ‘Report of the SAGE working group on vaccine hesitancy’ was administered during a span of two months among the general population from all administrative regions of Saudi Arabia, proceeding the launch of the vaccination campaign. In total, 879 out of 1600 subjects responded and completed the survey (response rate 54.9%). About 56 percent of the participants intended to be vaccinated. The predictors of a higher intention to vaccinate included those 50 years of age or older, male subjects, people suffering from systemic disease/s, subjects who were not previously infected with COVID-19, those who follow the updates about COVID-19 vaccines, and adults with a higher level of anxiety about contracting coronavirus (p < 0.05). Results from our study and other similar studies can aid policy makers and stakeholders in planning effective strategies based on the changing behavior of the population. Full article
Communication
Propylthiouracil-Induced Antineutrophil Cytoplasmic Antibody-Associated Vasculitis after COVID-19 Vaccination
Vaccines 2021, 9(8), 842; https://doi.org/10.3390/vaccines9080842 - 31 Jul 2021
Cited by 4 | Viewed by 1402
Abstract
We report the case of a patient who developed antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) after receiving the coronavirus disease 2019 (COVID-19) vaccine BNT162b (Pfizer–BioNTech). A 37-year-old Japanese woman had been taking propylthiouracil for Graves’ disease. She had erythema on her forearm on [...] Read more.
We report the case of a patient who developed antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) after receiving the coronavirus disease 2019 (COVID-19) vaccine BNT162b (Pfizer–BioNTech). A 37-year-old Japanese woman had been taking propylthiouracil for Graves’ disease. She had erythema on her forearm on the 12th day after receiving the first dose of the vaccine, fever on the 13th day, and redness and swelling of her left auricle on the 25th day. Her serum myeloperoxidase-ANCA and proteinase 3-ANCA levels, which were negative before the Graves’ disease treatment, were elevated. She had unilateral auricular symptoms but no other typical relapsing polychondritis findings. She was diagnosed with propylthiouracil-induced AAV. She was treated with oral glucocorticoids, and her symptoms improved. Propylthiouracil is considered to be the main cause of the onset of AAV in this case, but it cannot be ruled out that BNT162b may have had some effect on the onset of the disease. Although the development of propylthiouracil-induced AAV in this case may have been incidental and unrelated to the vaccination, this report provides important data for evaluating the safety of the vaccine. Full article
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Article
A Glimpse into the Diverse Cellular Immunity against SARS-CoV-2
Vaccines 2021, 9(8), 827; https://doi.org/10.3390/vaccines9080827 - 27 Jul 2021
Viewed by 1055
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular immune response has been shown to play a critical role in preventing severe illness or death in patients infected with SARS-CoV-2 or its variants. Given the multiple T-cell epitopes shared by wild-type virus and its [...] Read more.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific cellular immune response has been shown to play a critical role in preventing severe illness or death in patients infected with SARS-CoV-2 or its variants. Given the multiple T-cell epitopes shared by wild-type virus and its variants, we hypothesized that vaccines that target multiple T-cell epitopes of SARS-CoV-2 may provide a “universal protection” against the wild-type virus as well as its variants, even the heavily mutated ones. To test this, we assessed SARS-CoV-2-specific T-cell precursors in healthy individuals using overlapping peptide pools of SARS-CoV-2 structural and functional proteins, including spike (S), membrane (M), envelope (E), nucleocapsid (N), and protease (P) proteins as target antigens. Diverse T-cell precursor frequencies specific to these viral antigens were detected in healthy individuals, including high, medium, low, and no responders. This was further confirmed by efficient induction of anti-SARS-CoV-2 T-cell immune responses using ex vivo dendritic cell (DC)/T cell coculture. The results demonstrated T-cell responses consistent with the precursor frequencies of each of the individuals tested. Importantly, the combination of all five viral peptide pools induced the strongest cellular immune response, and further, after a DC-peptides re-stimulation, even the no responders developed an increased anti-viral T-cell response. These analyses recapitulate the presence of a broad anti-SARS-CoV-2 cellular immunity even in an immune naïve population, which could be enhanced by antigen presenting cells presenting the overlapping antigenic peptides. Given the critical role of cellular immunity in COVID-19 protection, these results have important implications for vaccine design and immunotherapy in fighting SARS-CoV-2 and its variants. Full article
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Article
Acceptance of COVID-19 Vaccination in Cancer Patients in Hong Kong: Approaches to Improve the Vaccination Rate
Vaccines 2021, 9(7), 792; https://doi.org/10.3390/vaccines9070792 - 16 Jul 2021
Cited by 7 | Viewed by 1515
Abstract
Emerging efficacy and safety data have led to the authorization of COVID-19 vaccines worldwide, but most trials excluded patients with active malignancies. This study evaluates the intended acceptance of COVID-19 vaccination in cancer patients in Hong Kong. Methods: 660 adult cancer patients received [...] Read more.
Emerging efficacy and safety data have led to the authorization of COVID-19 vaccines worldwide, but most trials excluded patients with active malignancies. This study evaluates the intended acceptance of COVID-19 vaccination in cancer patients in Hong Kong. Methods: 660 adult cancer patients received a survey, in paper or electronic format, between 31 January 2021 and 15 February 2021. The survey included patient’s clinical characteristics, perceptions of COVID-19 and vaccination, vaccine knowledge, cancer health literacy, and Hospital Anxiety and Depression scale (HADS). The primary outcome was the intended acceptance of COVID-19 vaccine in cancer patients. Multivariable analysis was performed to identify factors associated with intended acceptance. Results: The intended acceptance of COVID-19 vaccination was 17.9%. A total of 487 (73.8%) believed that vaccination could prevent them from infection. Over 70% worried about vaccine negative effects on cancer and its side effects. Factors associated with intended acceptance included higher level of “belief in vaccine on preventing them from getting COVID-19”, less worry about long-term side effects of vaccine, lower level of cancer health literacy, and normal HADS (Depression scale). Conclusions: To improve vaccine acceptance rate, public education campaigns specific to cancer patients to gain their trust in efficacy and relieve their worries are needed. Full article
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Article
Clinical Characteristics of Hospitalized COVID-19 Patients Who Received at Least One Dose of COVID-19 Vaccine
Vaccines 2021, 9(7), 781; https://doi.org/10.3390/vaccines9070781 - 13 Jul 2021
Cited by 18 | Viewed by 4444
Abstract
The clinical trials of the COVID-19 vaccines that are authorized in the European Union have revealed high efficacy in preventing symptomatic infections. However, during vaccination campaigns, some vaccine recipients, including those partially and fully vaccinated, will experience severe COVID-19, requiring hospitalization. This may [...] Read more.
The clinical trials of the COVID-19 vaccines that are authorized in the European Union have revealed high efficacy in preventing symptomatic infections. However, during vaccination campaigns, some vaccine recipients, including those partially and fully vaccinated, will experience severe COVID-19, requiring hospitalization. This may particularly concern patients with a diminished immune response to the vaccine, as well as non-responders. This work has retrospectively analyzed the 92 cases of patients who were hospitalized between 27 December 2020 and 31 May 2021 in four Polish healthcare units due to COVID-19, and who have previously received the COVID-19 vaccine (54.3% ≤ 14 days after the first dose, 26.1% > 14 days after the first dose, 7.6% ≤ 14 days after the second dose, and 12% > 14 days after the second dose). These patients represented a minute fraction (1.2%) of all the COVID-19 patients who were hospitalized during the same period in the same healthcare institutions. No significant differences in white blood count, absolute lymphocyte count nadir, C-reactive protein, interleukin-6, procalcitonin, oxygen saturation, lung involvement, and fever frequency were found between the recipients of the first and second vaccine dose. A total of 15 deaths were noted (1.1% of all fatal COVID-19 cases in the considered period and healthcare units), including six in patients who received the second dose (five > 14 days after the second dose)—three of these subjects were using immunosuppressive medicines, and two were confirmed to be vaccine non-responders. The study reassures that severe COVID-19 and deaths are not common in vaccinated individuals, highlights that the clinical course in such patients may not reveal any distinctive features, and advocates for close monitoring of those at a higher risk of vaccine failure. Full article
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Review
Multiple Sclerosis, Disease-Modifying Therapies and COVID-19: A Systematic Review on Immune Response and Vaccination Recommendations
Vaccines 2021, 9(7), 773; https://doi.org/10.3390/vaccines9070773 - 11 Jul 2021
Cited by 9 | Viewed by 2623
Abstract
Understanding the risks of COVID-19 in patients with Multiple Sclerosis (MS) receiving disease-modifying therapies (DMTs) and their immune reactions is vital to analyze vaccine response dynamics. A systematic review on COVID-19 course and outcomes in patients receiving different DMTs was conducted according to [...] Read more.
Understanding the risks of COVID-19 in patients with Multiple Sclerosis (MS) receiving disease-modifying therapies (DMTs) and their immune reactions is vital to analyze vaccine response dynamics. A systematic review on COVID-19 course and outcomes in patients receiving different DMTs was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Emerging data on SARS-CoV-2 vaccines was used to elaborate recommendations. Data from 4417 patients suggest that MS per se do not portend a higher risk of severe COVID-19. As for the general population, advanced age, comorbidities, and higher disability significantly impact COVID-19 outcomes. Most DMTs have a negligible influence on COVID-19 incidence and outcome, while for those causing severe lymphopenia and hypogammaglobulinemia, such as anti-CD20 therapies, there might be a tendency of increased hospitalization, worse outcomes and a higher risk of re-infection. Blunted immune responses have been reported for many DMTs, with vaccination implications. Clinical evidence does not support an increased risk of MS relapse or vaccination failure, but vaccination timing needs to be individually tailored. For cladribine and alemtuzumab, it is recommended to wait 3–6 months after the last cycle until vaccination. For the general anti-CD20 therapies, vaccination must be deferred toward the end of the cycle and the next dose administered at least 4–6 weeks after completing vaccination. Serological status after vaccination is highly encouraged. Growing clinical evidence and continuous surveillance are extremely important to continue guiding future treatment strategies and vaccination protocols. Full article
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Review
A Quantitative ELISA Protocol for Detection of Specific Human IgG against the SARS-CoV-2 Spike Protein
Vaccines 2021, 9(7), 770; https://doi.org/10.3390/vaccines9070770 - 09 Jul 2021
Cited by 1 | Viewed by 1386
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with at least 3.8 million deaths to date. For that reason, finding an efficient vaccine for this virus quickly became a global priority. The majority of vaccines now marketed are based [...] Read more.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with at least 3.8 million deaths to date. For that reason, finding an efficient vaccine for this virus quickly became a global priority. The majority of vaccines now marketed are based on the SARS-CoV-2 spike protein that has been described as the keystone for optimal immunization. In order to monitor SARS-CoV-2 spike-specific humoral responses generated by immunization or infection, we have developed a robust and reproducible enzyme-linked immunosorbent assay (ELISA) protocol. This protocol describes a method for quantitative detection of IgG antibodies against the SARS-CoV-2 spike protein using antigen-coated microtiter plates. Results showed that antibodies could be quantified between the range of 1.953 ng/mL to 500 ng/mL with limited inter- and intra-assay variability. Full article
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Communication
Humoral Response to SARS-Cov-2 Vaccination in Liver Transplant Recipients–A Single-Center Experience
Vaccines 2021, 9(7), 738; https://doi.org/10.3390/vaccines9070738 - 04 Jul 2021
Cited by 20 | Viewed by 1510
Abstract
Vaccination against SARS-CoV-2 infection is currently approved and shows favorable outcomes, but little known about antibody responses in solid organ transplant recipients, since these patients are known to have an impaired immune response upon vaccination and have not been included in admission studies. [...] Read more.
Vaccination against SARS-CoV-2 infection is currently approved and shows favorable outcomes, but little known about antibody responses in solid organ transplant recipients, since these patients are known to have an impaired immune response upon vaccination and have not been included in admission studies. We therefore analyzed immunogenicity in 43 liver transplant (LT) recipients in a median of 15 days (IQR, 12–24) after receiving two doses of the mRNA-based SARS-CoV-2 vaccine BNT162b2 following the standard protocol, and compared these results to a control group consisting of 20 healthcare workers (HCWs). Thirty-four of the 43 (79%) LT recipients developed antibodies, compared to 20 out of 20 (100%) in the control group (p = 0.047). The median SARS-CoV-2 IgG titer was significantly lower in the LT recipients compared to the control group (216 vs. >2080 BAU/mL, p = 0.0001). Age and sex distribution was similar in the LT patients that developed antibodies after vaccination compared to those who did not. Interestingly, the patients who received mycophenolate mofetil exhibited a reduced vaccination response compared to the other LT patients (5 of 11 (45.5%) vs. 29 of 32 (90.6%), p = 0.004). In conclusion, our data reveal lower immunogenicity of SARS-CoV-2 vaccine BNT162b2 in LT patients compared to the control group, but still show superior results compared to other solid organ transplant recipients reported so far. Full article
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Communication
Understanding Soaring Coronavirus Cases and the Effect of Contagion Policies in the UK
Vaccines 2021, 9(7), 735; https://doi.org/10.3390/vaccines9070735 - 03 Jul 2021
Viewed by 898
Abstract
The number of new daily SARS-CoV-2 infections experienced an abrupt increase during the last quarter of 2020 in almost every European country. The phenomenological explanation offered was a new mutation of the virus, first identified in the UK. We use publicly available data [...] Read more.
The number of new daily SARS-CoV-2 infections experienced an abrupt increase during the last quarter of 2020 in almost every European country. The phenomenological explanation offered was a new mutation of the virus, first identified in the UK. We use publicly available data in combination with a time-delayed controlled SIR model, which captures the effects of preventive measures on the spreading of the virus. We are able to reproduce the waves of infection occurred in the UK with a unique transmission rate, suggesting that the new SARS-CoV-2 variant is as transmissible as previous strains. Our findings indicate that the sudden surge in cases was, in fact, related to the relaxation of preventive measures and social awareness. We also simulate the combined effects of restrictions and vaccination campaigns in 2021, demonstrating that lockdown policies are not fully effective to flatten the curve. For effective mitigation, it is critical that the public keeps on high alert until vaccination reaches a critical threshold. Full article
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Communication
Fusion Protein of Rotavirus VP6 and SARS-CoV-2 Receptor Binding Domain Induces T Cell Responses
Vaccines 2021, 9(7), 733; https://doi.org/10.3390/vaccines9070733 - 02 Jul 2021
Cited by 2 | Viewed by 1026
Abstract
Vaccines based on mRNA and viral vectors are currently used in the frontline to combat the ongoing pandemic caused by the novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). However, there is still an urgent need for alternative vaccine technologies inducing/boosting long-lasting and cross-reactive [...] Read more.
Vaccines based on mRNA and viral vectors are currently used in the frontline to combat the ongoing pandemic caused by the novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). However, there is still an urgent need for alternative vaccine technologies inducing/boosting long-lasting and cross-reactive immunity in different populations. As a possible vaccine candidate, we employed the rotavirus VP6-protein platform to construct a fusion protein (FP) displaying receptor-binding domain (RBD) of SARS-CoV-2 spike protein (S) at the N-terminus of VP6. The recombinant baculovirus-insect cell produced VP6-RBD FP was proven antigenic in vitro and bound to the human angiotensin-converting enzyme 2 (hACE2) receptor. The FP was used to immunize BALB/c mice, and humoral- and T cell-mediated immune responses were investigated. SARS-CoV-2 RBD-specific T cells were induced at a high quantity; however, no RBD or S-specific antibodies were detected. The results suggest that conformational B cell epitopes might be buried inside the VP6, while RBD-specific T cell epitopes are available for T cell recognition after the processing and presentation of FP by the antigen-presenting cells. Further immunogenicity studies are needed to confirm these findings and to assess whether, under different experimental conditions, the VP6 platform may present SARS-CoV-2 antigens to B cells as well. Full article
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Communication
Serological Response in Lung Transplant Recipients after Two Doses of SARS-CoV-2 mRNA Vaccines
Vaccines 2021, 9(7), 708; https://doi.org/10.3390/vaccines9070708 - 30 Jun 2021
Cited by 19 | Viewed by 1331
Abstract
Background: Lung-transplant (LT) recipients are at high risk for COVID-19 due to immunosuppression and respiratory tropism of SARS-CoV-2. The information on the effect of COVID-19 mRNA vaccines to elicit immunogenic responses after a two-dose (2D) regimen in LT recipients is sparse. Thus, we [...] Read more.
Background: Lung-transplant (LT) recipients are at high risk for COVID-19 due to immunosuppression and respiratory tropism of SARS-CoV-2. The information on the effect of COVID-19 mRNA vaccines to elicit immunogenic responses after a two-dose (2D) regimen in LT recipients is sparse. Thus, we assessed the effect of Pfizer-BioNTech and Moderna mRNA vaccines’ 2D regimen on anti-spike responses in immunocompromised LT recipients. Methods: We utilized serum samples from LT recipients vaccinated for SARS-CoV-2 with 2D of either the Pfizer-BioNTech or Moderna vaccines and 2D-vaccinated naïve (non-transplanted and non-exposed to COVID-19) group. Antibody responses were assessed using the FDA-approved SARS-CoV-2 anti-nucleocapsid protein IgG assay (IgGNC), the SARS-CoV-2 anti-spike protein IgM assay (IgMSP), and the SARS-CoV-2 anti-spike protein IgG II assay (IgGSP). CD4+ T-cell activity was assessed as a marker of immune competence using the ImmuKnow® assay. Results: About 25% (18/73) of SARS-CoV-2 uninfected-LT patients generated a positive spike-IgG response following 2D of vaccines, with 36% (9/25) in the Moderna cohort and only 19% (9/48) in the Pfizer cohort. 2D in LT patients elicited a significantly lesser median IgGSP response (1.7 AU/mL, 95% CI: 0.6–7.5 AU/mL) compared to non-transplanted, uninfected naïve subjects (14,209 AU/mL, 95% CI: 11,261–18,836 AU/mL; p < 0.0001). In LT patients, the Moderna-evoked seropositivity trend was higher than Pfizer. Conclusion: 2D COVID-19 vaccination elicits a dampened serological response in LT patients. Whether assessing other arms of host immunity combined with a higher vaccine dose can better capture and elicit improved immunogenicity in this immunocompromised population warrants investigation. Full article
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Communication
Evaluation of SARS-CoV-2 Spike Protein Antibody Titers in Cord Blood after COVID-19 Vaccination during Pregnancy in Polish Healthcare Workers: Preliminary Results
Vaccines 2021, 9(6), 675; https://doi.org/10.3390/vaccines9060675 - 19 Jun 2021
Cited by 14 | Viewed by 4886
Abstract
Background: The coronavirus disease 2019 (COVID-19) pandemic has given rise to the need to develop a vaccine as quickly as possible. As pregnant women are at increased risk of contracting severe COVID-19, with higher mortality, it is essential to assess the safety of [...] Read more.
Background: The coronavirus disease 2019 (COVID-19) pandemic has given rise to the need to develop a vaccine as quickly as possible. As pregnant women are at increased risk of contracting severe COVID-19, with higher mortality, it is essential to assess the safety of the vaccines administered during pregnancy. Methods: The aim of this study was to determine the titer of specific maternal and cord antibodies against severe acute respiratory syndrome coronavirus 2 S protein after antenatal vaccination. The secondary objective was to evaluate the ratio of the umbilical cord to the maternal antibody titers. Patients included in the study were enrolled after undergoing voluntary vaccination against COVID-19 during pregnancy at different weeks of gestation. All patients analyzed in our initial study were vaccinated with the BNT162b2 mRNA COVID-19 vaccine. Results: The results of the current study document high anti-S total IgG antibody titers in cord serum at birth in all mother–infant pairs analyzed. The mean umbilical cord blood sample IgG antibody titer anti-S protein was 1026.51 U/mL (±SD 769.25). The mean cord-to-maternal anti–S IgG antibody ratio was 1.28 (±SD 0.798). A significant positive correlation was observed between the week of gestation at which the first dose was administered and the week of gestation at which the second dose was administered, and the respective cord-to-maternal ratio (r = 0.48; p = 0.0029) for the first dose and (r = 0.39; p = 0.0102) for the second dose. Conclusions: To date, despite the prevalence of COVID-19 vaccination, there is a lack of conclusive evidence supporting the safety and efficacy of vaccination of pregnant women. Therefore, the results we present are complementary. Our study suggests that maternal immunization may provide neonatal protection through the transplacental transfer of antibodies. Of particular importance is the demonstration that antibody transfer is correlated with the time from vaccination to delivery, which may allow future determination of the optimal timing of COVID-19 vaccination in pregnant women. Full article
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Article
Clinical Course and Risk Factors for In-Hospital Mortality of 205 Patients with SARS-CoV-2 Pneumonia in Como, Lombardy Region, Italy
Vaccines 2021, 9(6), 640; https://doi.org/10.3390/vaccines9060640 - 11 Jun 2021
Cited by 1 | Viewed by 1379
Abstract
The aim of this study is to explore risk factors for in-hospital mortality and describe the effectiveness of different treatment strategies of 205 laboratory-confirmed cases infected with SARS-CoV-2 during the Lombardy outbreak. All patients received the best supportive care and specific interventions that [...] Read more.
The aim of this study is to explore risk factors for in-hospital mortality and describe the effectiveness of different treatment strategies of 205 laboratory-confirmed cases infected with SARS-CoV-2 during the Lombardy outbreak. All patients received the best supportive care and specific interventions that included the main drugs being tested for repurposing to treat COVID-19, such as hydroxychloroquine, anticoagulation and antiviral drugs, steroids, and interleukin-6 pathway inhibitors. Clinical, laboratory, and treatment characteristics were analyzed with univariate and multivariate logistic regression methods to explore their impact on in-hospital mortality. Univariate analyses showed prognostic significance for age greater than 70 years, the presence of two or more relevant comorbidities, a P/F ratio less than 200 at presentation, elevated LDH (lactate dehydrogenase) and CRP (C-reactive protein) values, intermediate- or therapeutic-dose anticoagulation, hydroxychloroquine, early antiviral therapy with lopinavir/ritonavir, short courses of steroids, and tocilizumab therapy. Multivariable regression confirmed increasing odds of in-hospital death associated with age older than 70 years (OR 3.26) and a reduction in mortality for patients treated with anticoagulant (−0.37), antiviral lopinavir/ritonavir (−1.22), or steroid (−0.59) therapy. In contrast, hydroxychloroquine and tocilizumab have not been confirmed to have a significant effect in the treatment of SARS-CoV-2 pneumonia. Results from this real-life single-center experience are in agreement and confirm actual literature data on SARS-CoV-2 pneumonia in terms of both clinical risk factors for in-hospital mortality and the effectiveness of the different therapies proposed for the management of COVID19 disease. Full article
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Communication
COVID-19 Vaccination in Patients with Classic Kaposi’s Sarcoma
Vaccines 2021, 9(6), 632; https://doi.org/10.3390/vaccines9060632 - 10 Jun 2021
Cited by 1 | Viewed by 1182
Abstract
The novel coronavirus disease 2019 (COVID-19) has represented an overwhelming challenge for worldwide health systems. Patients with cancer are considered at higher risk for severe COVID-19 and increased mortality in case of infection. Although data on the novel severe acute respiratory syndrome coronavirus [...] Read more.
The novel coronavirus disease 2019 (COVID-19) has represented an overwhelming challenge for worldwide health systems. Patients with cancer are considered at higher risk for severe COVID-19 and increased mortality in case of infection. Although data on the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination in patients with cancer are limited, there is enough evidence supporting anti-infective vaccination in general in patients with active cancer, or with history of previous malignancy. Subjects with classic Kaposi’s sarcoma (KS) represent a small subset of cancer patients, which should be considered at heightened risk for infections due to several factors including age, and impaired immune function status. Several cases of human herpesviruses reactivation among critically ill COVID-19 patients have been described. Moreover, in case of severe infection and treatment with immunomodulating agents, patients with CKS are exposed at significant risk of viral reactivation and disease progression. Considering the baseline clinical risk factors of patients with CKS, and the complex interplay of the two viral agents, SARS-CoV-2 vaccination should be strongly recommended among patients with KS. KS represents an interesting field to study the interactions among chronic viral infections, SARS-CoV-2 and the host’s immune system. Prospective observational studies are needed to provide more insights on vaccine activity and safety among patients with cancer, optimal vaccine schedules, potential interactions with antineoplastic therapies, and other comorbidities including chronic viral infections. Full article
Brief Report
A Unique SARS-CoV-2 Spike Protein P681H Variant Detected in Israel
Vaccines 2021, 9(6), 616; https://doi.org/10.3390/vaccines9060616 - 08 Jun 2021
Cited by 13 | Viewed by 1786
Abstract
The routine detection, surveillance, and reporting of novel SARS-CoV-2 variants is crucial, as these threaten to hinder global vaccination efforts. Herein we report a novel local variant with a non-synonymous mutation in the spike (S) protein P681H. This local Israeli variant was not [...] Read more.
The routine detection, surveillance, and reporting of novel SARS-CoV-2 variants is crucial, as these threaten to hinder global vaccination efforts. Herein we report a novel local variant with a non-synonymous mutation in the spike (S) protein P681H. This local Israeli variant was not associated with a higher infection rate or higher prevalence. Furthermore, the local variant was successfully neutralized by sera from fully vaccinated individuals at a comparable level to the B.1.1.7 variant and an Israel wild-type strain. While it is not a variant of concern, routine monitoring by sequencing is still required. Full article
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Article
Could a New COVID-19 Mutant Strain Undermine Vaccination Efforts? A Mathematical Modelling Approach for Estimating the Spread of B.1.1.7 Using Ontario, Canada, as a Case Study
Vaccines 2021, 9(6), 592; https://doi.org/10.3390/vaccines9060592 - 03 Jun 2021
Cited by 4 | Viewed by 1655
Abstract
Infections represent highly dynamic processes, characterized by evolutionary changes and events that involve both the pathogen and the host. Among infectious agents, viruses, such as Severe Acute Respiratory Syndrome-related Coronavirus type 2 (SARS-CoV-2), the infectious agent responsible for the currently ongoing Coronavirus disease [...] Read more.
Infections represent highly dynamic processes, characterized by evolutionary changes and events that involve both the pathogen and the host. Among infectious agents, viruses, such as Severe Acute Respiratory Syndrome-related Coronavirus type 2 (SARS-CoV-2), the infectious agent responsible for the currently ongoing Coronavirus disease 2019 (COVID-2019) pandemic, have a particularly high mutation rate. Taking into account the mutational landscape of an infectious agent, it is important to shed light on its evolution capability over time. As new, more infectious strains of COVID-19 emerge around the world, it is imperative to estimate when these new strains may overtake the wild-type strain in different populations. Therefore, we developed a general-purpose framework to estimate the time at which a mutant variant is able to take over a wild-type strain during an emerging infectious disease outbreak. In this study, we used COVID-19 as a case-study; however, the model is adaptable to any emerging pathogen. We devised a two-strain mathematical framework to model a wild- and a mutant-type viral population and fit cumulative case data to parameterize the model, using Ontario as a case study. We found that, in the context of under-reporting and the current case levels, a variant strain was unlikely to dominate until March/April 2021. The current non-pharmaceutical interventions in Ontario need to be kept in place longer even with vaccination in order to prevent another outbreak. The spread of a variant strain in Ontario will likely be observed by a widened peak of the daily reported cases. If vaccine efficacy is maintained across strains, then it is still possible to achieve high levels of immunity in the population by the end of 2021. Our findings have important practical implications in terms of public health as policy- and decision-makers are equipped with a mathematical tool that can enable the estimation of the take-over of a mutant strain of an emerging infectious disease. Full article
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Article
An Immunoinformatics Approach for SARS-CoV-2 in Latam Populations and Multi-Epitope Vaccine Candidate Directed towards the World’s Population
Vaccines 2021, 9(6), 581; https://doi.org/10.3390/vaccines9060581 - 01 Jun 2021
Cited by 2 | Viewed by 2159
Abstract
The coronavirus pandemic is a major public health crisis affecting global health systems with dire socioeconomic consequences, especially in vulnerable regions such as Latin America (LATAM). There is an urgent need for a vaccine to help control contagion, reduce mortality and alleviate social [...] Read more.
The coronavirus pandemic is a major public health crisis affecting global health systems with dire socioeconomic consequences, especially in vulnerable regions such as Latin America (LATAM). There is an urgent need for a vaccine to help control contagion, reduce mortality and alleviate social costs. In this study, we propose a rational multi-epitope candidate vaccine against SARS-CoV-2. Using bioinformatics, we constructed a library of potential vaccine peptides, based on the affinity of the most common major human histocompatibility complex (HLA) I and II molecules in the LATAM population to predict immunological complexes among antigenic, non-toxic and non-allergenic peptides extracted from the conserved regions of 92 proteomes. Although HLA-C, had the greatest antigenic peptide capacity from SARS-CoV-2, HLA-B and HLA-A, could be more relevant based on COVID-19 risk of infection in LATAM countries. We also used three-dimensional structures of SARS-CoV-2 proteins to identify potential regions for antibody production. The best HLA-I and II predictions (with increased coverage in common alleles and regions evoking B lymphocyte responses) were grouped into an optimized final multi-epitope construct containing the adjuvants Beta defensin-3, TpD, and PADRE, which are recognized for invoking a safe and specific immune response. Finally, we used Molecular Dynamics to identify the multi-epitope construct which may be a stable target for TLR-4/MD-2. This would prove to be safe and provide the physicochemical requirements for conducting experimental tests around the world. Full article
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Article
Maximization of Open Hospital Capacity under Shortage of SARS-CoV-2 Vaccines—An Open Access, Stochastic Simulation Tool
Vaccines 2021, 9(6), 546; https://doi.org/10.3390/vaccines9060546 - 22 May 2021
Cited by 2 | Viewed by 1119
Abstract
Motive. The Covid-19 pandemic has led to the novel situation that hospitals must prioritize staff for a vaccine rollout while there is acute shortage of the vaccine. In spite of the availability of guidelines from state agencies, there is partial confusion about what [...] Read more.
Motive. The Covid-19 pandemic has led to the novel situation that hospitals must prioritize staff for a vaccine rollout while there is acute shortage of the vaccine. In spite of the availability of guidelines from state agencies, there is partial confusion about what an optimal rollout plan is. This study investigates effects in a hospital model under different rollout schemes. Methods. A simulation model is implemented in VBA, and is studied for parameter variation in a predefined hospital setting. The implemented code is available as open access supplement. Main results. A rollout scheme assigning vaccine doses to staff primarily by staff’s pathogen exposure maximizes the predicted open hospital capacity when compared to a rollout based on a purely hierarchical prioritization. The effect increases under resource scarcity and greater disease activity. Nursing staff benefits most from an exposure focused rollout. Conclusions. The model employs SARS-CoV-2 parameters; nonetheless, effects observable in the model are transferable to other infectious diseases. Necessary future prioritization plans need to consider pathogen characteristics and social factors. Full article
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Article
Local Sustained GM-CSF Delivery by Genetically Engineered Encapsulated Cells Enhanced Both Cellular and Humoral SARS-CoV-2 Spike-Specific Immune Response in an Experimental Murine Spike DNA Vaccination Model
Vaccines 2021, 9(5), 484; https://doi.org/10.3390/vaccines9050484 - 10 May 2021
Cited by 1 | Viewed by 1398
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with recurrences. Therefore, finding a vaccine for this virus became a priority for the scientific community. The SARS-CoV-2 spike protein has been described as the keystone for viral entry into cells [...] Read more.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic with recurrences. Therefore, finding a vaccine for this virus became a priority for the scientific community. The SARS-CoV-2 spike protein has been described as the keystone for viral entry into cells and effective immune protection against SARS-CoV-2 is elicited by this protein. Consequently, many commercialized vaccines focus on the spike protein and require the use of an optimal adjuvant during vaccination. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has demonstrated a powerful enhancement of acquired immunity against many pathogens when delivered in a sustained and local manner. In this context, we developed an encapsulated cell-based technology consisting of a biocompatible, semipermeable capsule for secretion of GM-CSF. In this study, we investigated whether murine GM-CSF (muGM-CSF) represents a suitable adjuvant for SARS-CoV-2 immunization, and which delivery strategy for muGM-CSF could be most beneficial. To test this, different groups of mice were immunized with intra-dermal (i.d.) electroporated spike DNA in the absence or presence of recombinant or secreted muGM-CSF. Results demonstrated that adjuvanting a spike DNA vaccine with secreted muGM-CSF resulted in enhancement of specific cellular and humoral immune responses against SARS-CoV-2. Our data also highlighted the importance of delivery strategies to the induction of cellular and humoral-mediated responses. Full article
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Article
Sensitivity to COVID-19 Vaccine Effectiveness and Safety in Shanghai, China
Vaccines 2021, 9(5), 472; https://doi.org/10.3390/vaccines9050472 - 07 May 2021
Cited by 10 | Viewed by 1761
Abstract
Several COVID-19 vaccines have been on the market since early 2021 and may vary in their effectiveness and safety. This study characterizes hesitancy about accepting COVID-19 vaccines among parents in Shanghai, China, and identifies how sensitive they are to changes in vaccine safety [...] Read more.
Several COVID-19 vaccines have been on the market since early 2021 and may vary in their effectiveness and safety. This study characterizes hesitancy about accepting COVID-19 vaccines among parents in Shanghai, China, and identifies how sensitive they are to changes in vaccine safety and effectiveness profiles. Schools in each township of Minhang District, Shanghai, were sampled, and parents in the WeChat group of each school were asked to participate in this cross-sectional Internet-based survey. Parents responded to questions about hesitancy and were given information about five different COVID-19 vaccine candidates, the effectiveness of which varied between 50 and 95% and which had a risk of fever as a side effect between 5 and 20%. Overall, 3673 parents responded to the survey. Almost 90% would accept a vaccine for themselves (89.7%), for their child (87.5%) or for an elderly parent (88.5%) with the most ideal attributes (95% effectiveness with 5% risk of fever). But with the least ideal attributes (50% effectiveness and a 20% risk of fever) these numbers dropped to 33.5%, 31.3%, and 31.8%, respectively. Vaccine hesitancy, age at first child’s birth, and relative income were all significantly related to sensitivity to vaccine safety and effectiveness. Parents showed a substantial shift in attitudes towards a vaccine based on its safety and effectiveness profile. These findings indicate that COVID-19 vaccine acceptance may be heavily influenced by how effective the vaccine actually is and could be impeded or enhanced based on vaccines already on the market. Full article
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Article
Attitudes of Patients with Cancer towards Vaccinations—Results of Online Survey with Special Focus on the Vaccination against COVID-19
Vaccines 2021, 9(5), 411; https://doi.org/10.3390/vaccines9050411 - 21 Apr 2021
Cited by 18 | Viewed by 2304
Abstract
Recently developed COVID-19 vaccines significantly reduce the risk of severe coronavirus disease, which is essential in the particularly vulnerable cancer patient population. There is a growing anti-vaccine concern that may affect the success of the fight against the SARS-CoV2 pandemic. To evaluate opinions [...] Read more.
Recently developed COVID-19 vaccines significantly reduce the risk of severe coronavirus disease, which is essential in the particularly vulnerable cancer patient population. There is a growing anti-vaccine concern that may affect the success of the fight against the SARS-CoV2 pandemic. To evaluate opinions and attitudes toward vaccination, we conducted an anonymous online survey among Polish patients diagnosed with cancer. We analyzed how socio-demographic factors, type of cancer, comorbidities, previous influenza vaccinations, and information sources affect the general willingness and opinions about vaccinations, emphasizing vaccination against COVID-19. Six hundred thirty-five patients (80.2% female) participated in the study. A positive attitude towards vaccination was presented by 73.7%, neutral by 17.8%, while negative by 8.5%. Willingness to get vaccinated was declared by 60.3%, 23.5% were unwilling, and 16.2% were undecided. Significant predictors of willingness were education, marital status, active anti-cancer treatment, previous influenza vaccination, and positive attitude towards vaccinations. Patients with cancer have concerns regarding safety, effectiveness, and the process of development of the COVID-19 vaccine. Overall, patients with cancer present positive attitudes towards COVID-19 vaccination but required sufficient information on its efficacy and side effects. Full article
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Article
Analysis of Thrombotic Adverse Reactions of COVID-19 AstraZeneca Vaccine Reported to EudraVigilance Database
Vaccines 2021, 9(4), 393; https://doi.org/10.3390/vaccines9040393 - 16 Apr 2021
Cited by 38 | Viewed by 8475
Abstract
The development of safe, effective, affordable vaccines against COVID-19 remains the cornerstone to mitigating this pandemic. Early in December 2020, multiple research groups had designed potential vaccines. From 11 March 2021, several European countries temporarily suspended the use of the Oxford–AstraZeneca vaccine amid [...] Read more.
The development of safe, effective, affordable vaccines against COVID-19 remains the cornerstone to mitigating this pandemic. Early in December 2020, multiple research groups had designed potential vaccines. From 11 March 2021, several European countries temporarily suspended the use of the Oxford–AstraZeneca vaccine amid reports of blood clot events and the death of a vaccinated person, despite the European Medicines Agency (EMA) and the World Health Organization’s assurance that there was no indication that vaccination was linked. This study aimed to identify and analyse the thrombotic adverse reactions associated with the Oxford–AstraZeneca vaccine. This was a retrospective descriptive study using spontaneous reports submitted to the EudraVigilance database in the period from 17 February to 12 March 2021. There were 54,571 adverse reaction reports, of which 28 were associated with thrombotic adverse reactions. Three fatalities were related to pulmonary embolism; one fatality to thrombosis. With 17 million people having had the AstraZeneca vaccine, these are extremely rare events The EMA’s Pharmacovigilance Risk Assessment Committee (18 March 2021) concluded that the vaccine was safe, effective and the benefits outweighed the risks. Conducting further analyses based on more detailed thrombotic adverse event reports, including patients’ characteristics and comorbidities, may enable assessment of the causality with higher specificity. Full article
Article
Enhancing COVID-19 Vaccines Acceptance: Results from a Survey on Vaccine Hesitancy in Northern Italy
Vaccines 2021, 9(4), 378; https://doi.org/10.3390/vaccines9040378 - 13 Apr 2021
Cited by 39 | Viewed by 5394
Abstract
In March 2021, the coronavirus disease 2019 (COVID-19) pandemic still poses a threat to the global population, and is a public health challenge that needs to be overcome. Now more than ever, action is needed to tackle vaccine hesitancy, especially in light of [...] Read more.
In March 2021, the coronavirus disease 2019 (COVID-19) pandemic still poses a threat to the global population, and is a public health challenge that needs to be overcome. Now more than ever, action is needed to tackle vaccine hesitancy, especially in light of the availability of effective and safe vaccines. A cross-sectional online survey was carried out on a representative random sample of 1011 citizens from the Emilia-Romagna region, in Italy, in January 2021. The questionnaire collected information on socio-demographics, comorbidities, past vaccination refusal, COVID-19-related experiences, risk perception of infection, and likelihood to accept COVID-19 vaccination. Multiple logistic regression analyses and classification tree analyses were performed to identify significant predictors of vaccine hesitancy and to distinguish groups with different levels of hesitancy. Overall, 31.1% of the sample reported hesitancy. Past vaccination refusal was the key discriminating variable followed by perceived risk of infection. Other significant predictors of hesitancy were: ages between 35 and 54 years, female gender, low educational level, low income, and absence of comorbidities. The most common concerns about the COVID-19 vaccine involved safety (54%) and efficacy (27%). Studying the main determinants of vaccine hesitancy can help with targeting vaccination strategies, in order to gain widespread acceptance—a key path to ensure a rapid way out of the current pandemic emergency. Full article
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Article
Soluble Spike DNA Vaccine Provides Long-Term Protective Immunity against SARS-CoV-2 in Mice and Nonhuman Primates
Vaccines 2021, 9(4), 307; https://doi.org/10.3390/vaccines9040307 - 24 Mar 2021
Cited by 13 | Viewed by 2373
Abstract
The unprecedented and rapid spread of SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) has motivated the need for a rapidly producible and scalable vaccine. Here, we developed a synthetic soluble SARS-CoV-2 spike (S) DNA-based vaccine candidate, GX-19. In mice, immunization with GX-19 elicited not only [...] Read more.
The unprecedented and rapid spread of SARS-CoV-2 (severe acute respiratory syndrome-coronavirus-2) has motivated the need for a rapidly producible and scalable vaccine. Here, we developed a synthetic soluble SARS-CoV-2 spike (S) DNA-based vaccine candidate, GX-19. In mice, immunization with GX-19 elicited not only S-specific systemic and pulmonary antibody responses but also Th1-biased T cell responses in a dose-dependent manner. GX-19-vaccinated nonhuman primates seroconverted rapidly and exhibited a detectable neutralizing antibody response as well as multifunctional CD4+ and CD8+ T cell responses. Notably, when the immunized nonhuman primates were challenged at 10 weeks after the last vaccination with GX-19, they had reduced viral loads in contrast to non-vaccinated primates as a control. These findings indicate that GX-19 vaccination provides a durable protective immune response and also support further development of GX-19 as a vaccine candidate for SARS-CoV-2. Full article
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Article
Acceptance of a COVID-19 Vaccine in Japan during the COVID-19 Pandemic
Vaccines 2021, 9(3), 210; https://doi.org/10.3390/vaccines9030210 - 03 Mar 2021
Cited by 82 | Viewed by 8685
Abstract
Vaccination could be a key protective measure against coronavirus disease 2019 (COVID-19), and it is important to understand the acceptability of the COVID-19 vaccine among the general public. However, there is no study on the acceptance of a COVID-19 vaccine in Japan. Therefore, [...] Read more.
Vaccination could be a key protective measure against coronavirus disease 2019 (COVID-19), and it is important to understand the acceptability of the COVID-19 vaccine among the general public. However, there is no study on the acceptance of a COVID-19 vaccine in Japan. Therefore, this study aimed to describe the COVID-19 vaccine acceptance and hesitancy situation in Japan and assess the factors associated with such issues. This was a cross-sectional study based on an internet survey completed by 2956 people. Participants were asked to indicate how likely they were to get vaccinated for COVID-19. In addition, the participants responded to questions regarding sociodemographic factors, attitudes, and beliefs regarding COVID-19 infection and vaccination. The proportion of participants with a high likelihood of getting a COVID-19 vaccine was 62.1%. Multiple logistic regression analysis showed that vaccine acceptance was lower among several sociodemographic groups, such as women, adults aged 20–49 years, and those with a low-income level. Several psychological factors, especially the perceived effectiveness of the COVID-19 vaccine, and willingness to protect others by getting oneself vaccinated, were associated with vaccine acceptance. Our results indicate that the perceived effectiveness of the vaccine and willingness to protect others may play an important role in the acceptance of the COVID-19 vaccine. Full article
Review
Are We Ready for the Arrival of the New COVID-19 Vaccinations? Great Promises and Unknown Challenges Still to Come
Vaccines 2021, 9(2), 173; https://doi.org/10.3390/vaccines9020173 - 18 Feb 2021
Cited by 7 | Viewed by 2604
Abstract
While the SARS-CoV-2 pandemic continues to strike and collect its death toll throughout the globe, as of 31 January 2021, the vaccine candidates worldwide were 292, of which 70 were in clinical testing. Several vaccines have been approved worldwide, and in particular, three [...] Read more.
While the SARS-CoV-2 pandemic continues to strike and collect its death toll throughout the globe, as of 31 January 2021, the vaccine candidates worldwide were 292, of which 70 were in clinical testing. Several vaccines have been approved worldwide, and in particular, three have been so far authorized for use in the EU. Vaccination can be, in fact, an efficient way to mitigate the devastating effect of the pandemic and offer protection to some vulnerable strata of the population (i.e., the elderly) and reduce the social and economic burden of the current crisis. Regardless, a question is still open: after vaccination availability for the public, will vaccination campaigns be effective in reaching all the strata and a sufficient number of people in order to guarantee herd immunity? In other words: after we have it, will we be able to use it? Following the trends in vaccine hesitancy in recent years, there is a growing distrust of COVID-19 vaccinations. In addition, the online context and competition between pro- and anti-vaxxers show a trend in which anti-vaccination movements tend to capture the attention of those who are hesitant. Describing this context and analyzing its possible causes, what interventions or strategies could be effective to reduce COVID-19 vaccine hesitancy? Will social media trend analysis be helpful in trying to solve this complex issue? Are there perspectives for an efficient implementation of COVID-19 vaccination coverage as well as for all the other vaccinations? Full article
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