Next Issue
Volume 9, October
Previous Issue
Volume 9, August
 
 

Vaccines, Volume 9, Issue 9 (September 2021) – 110 articles

Cover Story (view full-size image): The receptor binding domain (RBD) of the SARS-CoV-2 spike (S) protein was expressed in the glycol-engineered-tobacco plant Nicotiana benthamiana to provide a candidate subunit vaccine. The immunogenicity of the plant-expressed RBD candidate vaccine was evaluated in female BALB/c mice. Intermuscular administration of three doses of 10 µg of RBD alone or formulated with adjuvant induces a high titer of RBD specific IgG antibodies. The induced humoral response was found to be Th-2 type, as revealed by high IgG1 antibodies. The immunized mice sera showed the capacity of neutralizing live SARS-CoV-2 as demonstrated by high titer (FRNT50 = 6412) in focus reduction neutralization test (FRNT) assay. These findings provide a strong foundation to further develop plant-expressed RBD antigens for an effective, safe, and inexpensive SARS-CoV-2 vaccine. View this paper
  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:
Article
Intent to Vaccinate SARS-CoV-2 Infected Children in US Households: A Survey
Vaccines 2021, 9(9), 1049; https://doi.org/10.3390/vaccines9091049 - 21 Sep 2021
Cited by 9 | Viewed by 1875
Abstract
A paucity of data exists evaluating a guardian’s intent to vaccinate their child against COVID-19 in the United States. We administered 102 first (April–November 2020) and 45 second (December–January 2020–2021) surveys to guardians of children (<18 years) who had a laboratory-confirmed diagnosis of [...] Read more.
A paucity of data exists evaluating a guardian’s intent to vaccinate their child against COVID-19 in the United States. We administered 102 first (April–November 2020) and 45 second (December–January 2020–2021) surveys to guardians of children (<18 years) who had a laboratory-confirmed diagnosis of COVID-19 and assessed their intent to give a COVID-19 vaccine to their child, when one becomes available. The first and second surveys of the same cohort of guardians were conducted before and following the press releases detailing the adult Pfizer-BioNTech and Moderna Phase 3 results. Both surveys included an intent-to-vaccinate question using the subjective language of “if a safe and effective vaccine” became available, and a second question was added to second surveys using the objective language of “would prevent 19 of 20 people from getting disease”. When using subjective language, 24 of 45 (53%) guardians endorsed vaccine administration for their children in the first survey, which decreased to 21 (46%) in the second survey. When adding objective language, acceptance of vaccination increased to 31 (69%, p = 0.03). Common reasons for declining vaccination were concerns about adverse effects and/or vaccine safety. Providing additional facts on vaccine efficacy increased vaccine acceptance. Evidence-based strategies are needed to increase pediatric COVID-19 vaccine uptake. Full article
Show Figures

Figure 1

Systematic Review
COVID-19 Vaccines in Cancer Patients. Seropositivity and Safety. Systematic Review and Meta-Analysis
Vaccines 2021, 9(9), 1048; https://doi.org/10.3390/vaccines9091048 - 20 Sep 2021
Cited by 20 | Viewed by 3129
Abstract
Patients with cancer are among the most vulnerable groups of the COVID-19 pandemic, whereas vaccinations can represent a cornerstone in overcoming the pandemic itself. However, cancer patients were excluded from clinical trials for COVID-19 vaccinations, and thus the data on the immunogenicity and [...] Read more.
Patients with cancer are among the most vulnerable groups of the COVID-19 pandemic, whereas vaccinations can represent a cornerstone in overcoming the pandemic itself. However, cancer patients were excluded from clinical trials for COVID-19 vaccinations, and thus the data on the immunogenicity and safety of COVID-19 vaccines in cancer patients are limited. In this systematic review, we assessed the seroconversion rate and the safety of COVID-19 vaccinations in cancer patients. We searched a bibliographic database up until 31 July 2021. Utilizing inclusion criteria, six studies were selected and analyzed for this meta-analysis. This included 621 cancer patients and 256 controls. Results show that patients with solid tumors show adequate antibody responses (>90%), though the antibody titers were significantly lower than those of healthy controls. Similarly, a significantly lower rate of seroconversion was registered in patients with hematologic malignances. The vaccines showed a good safety profile; no grade 3–4 adverse events were registered. This review demonstrates generally high immunogenicity from COVID-19 vaccines in patients with cancer, with better results for solid tumors than hematological malignances, and with a good safety profile. Full article
(This article belongs to the Special Issue Vaccines against Infectious Diseases and Cancer)
Show Figures

Figure 1

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 14 | Viewed by 5971
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
(This article belongs to the Collection COVID-19 Vaccines and Vaccination)
Show Figures

Figure 1

Article
Expanding Protection Motivation Theory to Explain Willingness of COVID-19 Vaccination Uptake among Taiwanese University Students
Vaccines 2021, 9(9), 1046; https://doi.org/10.3390/vaccines9091046 - 19 Sep 2021
Cited by 28 | Viewed by 3681
Abstract
Vaccination appears to be one of the effective strategies to control the COVID-19 pandemic. However, the challenge of vaccine hesitancy may lower the uptake rate and affect overall vaccine efficacy. Being a low-risk group in terms of serious consequences of infection, university students [...] Read more.
Vaccination appears to be one of the effective strategies to control the COVID-19 pandemic. However, the challenge of vaccine hesitancy may lower the uptake rate and affect overall vaccine efficacy. Being a low-risk group in terms of serious consequences of infection, university students may possess low motivation to get vaccinated. Therefore, an expanded Protection Motivation Theory (PMT) incorporating perceived knowledge, adaptive response, and maladaptive response was proposed to investigate the COVID-19 vaccination intention among Taiwanese university students. University students (n = 924; 575 males; mean age = 25.29 years) completed an online survey during January to February 2021. The proposed expanded PMT model was examined using structural equation modeling (SEM). The results showed that perceived knowledge was significantly associated with coping appraisal (standardized coefficient (β) = 0.820; p < 0.001), and coping appraisal was significantly associated with adaptive response (β = 0.852; p < 0.001), maladaptive response (β = 0.300; p < 0.001) and intention (β = 0.533; p = 0.009). Moreover, maladaptive response (β = −0.173; p = 0.001) but not adaptive response (β = 0.148; p = 0.482) was significantly and negatively associated with intention. The present study’s results demonstrated a positive path between perceived knowledge, coping appraisal, and intention among university students. Therefore, improving knowledge among this population may increase the intention to uptake the vaccine. Full article
(This article belongs to the Special Issue Vaccination and Public Health Version II: COVID-19 Vaccination)
Show Figures

Figure 1

Commentary
Selection of Filovirus Isolates for Vaccine Development Programs
Vaccines 2021, 9(9), 1045; https://doi.org/10.3390/vaccines9091045 - 19 Sep 2021
Cited by 5 | Viewed by 1446
Abstract
The continuing outbreaks of ebola virus disease highlight the ongoing threat posed by filoviruses. Fortunately, licensed vaccines and therapeutics are now available for Zaire ebolavirus. However, effective medical countermeasures, such as vaccines for other filoviruses such as Sudan ebolavirus and the Marburg [...] Read more.
The continuing outbreaks of ebola virus disease highlight the ongoing threat posed by filoviruses. Fortunately, licensed vaccines and therapeutics are now available for Zaire ebolavirus. However, effective medical countermeasures, such as vaccines for other filoviruses such as Sudan ebolavirus and the Marburg virus, are presently in early stages of development and, in the absence of a large outbreak, would require regulatory approval via the U.S. Food and Drug Administration (FDA) Animal Rule. The selection of an appropriate animal model and virus challenge isolates for nonclinical studies are critical aspects of the development program. Here, we have focused on the recommendation of challenge isolates for Sudan ebolavirus and Marburg virus. Based on analyses led by the Filovirus Animal and Nonclinical Group (FANG) and considerations for strain selection under the FDA Guidance for the Animal Rule, we propose prototype virus isolates for use in nonclinical challenge studies. Full article
Article
Changes in Mental Health and Preventive Behaviors before and after COVID-19 Vaccination: A Propensity Score Matching (PSM) Study
Vaccines 2021, 9(9), 1044; https://doi.org/10.3390/vaccines9091044 - 19 Sep 2021
Cited by 11 | Viewed by 4061
Abstract
Mass vaccination against the COVID-19 pandemic is ongoing worldwide to achieve herd immunity among the general population. However, little is known about how the COVID-19 vaccination would affect mental health and preventive behaviors toward the COVID-19 pandemic. In this study, we conducted a [...] Read more.
Mass vaccination against the COVID-19 pandemic is ongoing worldwide to achieve herd immunity among the general population. However, little is known about how the COVID-19 vaccination would affect mental health and preventive behaviors toward the COVID-19 pandemic. In this study, we conducted a cross-sectional survey to address this issue among 4244 individuals at several COVID-19 vaccination sites in Guangzhou, China. Using univariate analysis and multiple linear regression models, we found that major demographic characteristics, such as biological sex, age, education level, and family per capita income, are the dominant influencing factors associated with health beliefs, mental health, and preventive behaviors. After propensity score matching (PSM) treatment, we further assessed the changes in the scores of health belief, mental health, and preventive behaviors between the pre-vaccination group and the post-vaccination group. When compared to individuals in the pre-vaccination group, a moderate but statistically significant lower score was observed in the post-vaccination group (p = 0.010), implying possibly improved psychological conditions after COVID-19 vaccination. In addition, there was also a moderate but statistically higher score of preventive behaviors in the post-vaccination group than in the pre-vaccination group (p < 0.001), suggesting a higher probability to take preventive measures after COVID-19 vaccination. These findings have implications for implementing non-pharmaceutical interventions combined with mass vaccination to control the rebound of COVID-19 outbreaks. Full article
Show Figures

Figure 1

Article
Decrease of Pneumococcal Community-Acquired Pneumonia Hospitalization and Associated Complications in Children after the Implementation of the 13-Valent Pneumococcal Conjugate Vaccine (PCV13) in Taiwan
Vaccines 2021, 9(9), 1043; https://doi.org/10.3390/vaccines9091043 - 18 Sep 2021
Cited by 1 | Viewed by 1441
Abstract
The impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on overall community-acquired pneumonia (CAP) and disease severity still needs thorough evaluation. In this study, we retrieve both pneumococcal CAP (P-CAP) and unspecific CAP (U-CAP) inpatient data from the Taiwan National Health Insurance Database [...] Read more.
The impact of the 13-valent pneumococcal conjugate vaccine (PCV13) on overall community-acquired pneumonia (CAP) and disease severity still needs thorough evaluation. In this study, we retrieve both pneumococcal CAP (P-CAP) and unspecific CAP (U-CAP) inpatient data from the Taiwan National Health Insurance Database (NHID) between 2005 and 2016. The interrupted time-series (ITS) analysis was performed to compare the incidence trend before and after the implementation of PCV13. After PCV13 implementation, there is a significant decreasing trend of P-CAP hospitalization, especially in children <1 year, 2–5 years, adults aged 19–65 years, 66 years, or older (all p value < 0.05). This corresponds to a 59% reduction in children <1 year, 47% in children aged 2–5 years, 39% in adult aged 19–65 years, and 41% in elderly aged 66 years or older. The intensive care rate (6.8% to 3.9%), severe pneumonia cases (21.7 to 14.5 episodes per 100,000 children–years), and the need for invasive procedures (4.3% to 2.0%) decreased in children aged 2–5 years (p value < 0.0001) with P-CAP. This PCV13 implementation program in Taiwan not only reduced the incidence of P-CAP, but also attenuated disease severity, especially in children aged 2–5 years. Full article
(This article belongs to the Special Issue Vaccines against Pneumococcal Infection)
Show Figures

Figure 1

Article
Age and Smoking Predict Antibody Titres at 3 Months after the Second Dose of the BNT162b2 COVID-19 Vaccine
Vaccines 2021, 9(9), 1042; https://doi.org/10.3390/vaccines9091042 - 18 Sep 2021
Cited by 34 | Viewed by 2780
Abstract
Objective: We aimed to determine antibody (Ab) titres 3 months after the second dose of the BNT162b2 coronavirus disease-2019 (COVID-19) vaccine and to explore clinical variables predicting these titres in Japan. Methods: We enrolled 378 healthcare workers (255 women, 123 men) whose blood [...] Read more.
Objective: We aimed to determine antibody (Ab) titres 3 months after the second dose of the BNT162b2 coronavirus disease-2019 (COVID-19) vaccine and to explore clinical variables predicting these titres in Japan. Methods: We enrolled 378 healthcare workers (255 women, 123 men) whose blood samples were collected 91 ± 15 days after the second of two inoculations of the BNT162b2 COVID-19 mRNA vaccine (Pfizer/BioNTech) given 3 weeks apart. Medical histories and demographic characteristics were recorded using a structured self-reported questionnaire. The relationships between Ab titres and these factors were analysed. Results: Median age (interquartile range (IQR)) of the participants was 44 (32–54) years. Median Ab titre (IQR) against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antigen was 764 (423–1140) U/mL. Older participants had significantly lower Ab titres; median (IQR) Ab titres were 942 (675–1390) and 1095 (741–1613) U/mL in men and women in their 20s, respectively, but 490 (297–571) and 519 (285–761) U/mL in men and women in their 60–70s, respectively. In the age-adjusted analysis, the only risk factors for lower Ab titres were male sex and smoking. However, the sex difference may have arisen from the sex difference in smoking rate. Moreover, Ab titres were significantly lower in current smokers than in ex-smokers. Conclusions: The most important factors associated with low Ab titres were age and smoking habit. In particular, current smoking status caused lower Ab titres, and smoking cessation before vaccination may improve the individual efficacy of the BNT162b2 vaccine. Full article
(This article belongs to the Topic Global Analysis of SARS-CoV-2 Serology)
Show Figures

Figure 1

Review
A Novel Approach against Salmonella: A Review of Polymeric Nanoparticle Vaccines for Broilers and Layers
Vaccines 2021, 9(9), 1041; https://doi.org/10.3390/vaccines9091041 - 18 Sep 2021
Cited by 4 | Viewed by 3174
Abstract
This work discusses the present-day limitations of current commercial Salmonella vaccines for broilers and layers and explores a novel approach towards poultry vaccination using biodegradable nanoparticle vaccines against Salmonella. With the increasing global population and poultry production and consumption, Salmonella is a [...] Read more.
This work discusses the present-day limitations of current commercial Salmonella vaccines for broilers and layers and explores a novel approach towards poultry vaccination using biodegradable nanoparticle vaccines against Salmonella. With the increasing global population and poultry production and consumption, Salmonella is a potential health risk for humans. The oral administration of killed or inactivated vaccines would provide a better alternative to the currently commercially available Salmonella vaccines for poultry. However, there are currently no commercial oral killed-vaccines against Salmonella for use in broilers or layers. There is a need for novel and effective interventions in the poultry industry. Polymeric nanoparticles could give way to an effective mass-administered mucosal vaccination method for Salmonella. The scope of this work is limited to polymeric nanoparticles against Salmonella for use in broilers and layers. This review is based on the information available at the time of the investigation. Full article
Show Figures

Figure 1

Case Report
A Case of Rubella Caused by Rubella Vaccination
Vaccines 2021, 9(9), 1040; https://doi.org/10.3390/vaccines9091040 - 18 Sep 2021
Cited by 3 | Viewed by 1252
Abstract
We present an extremely rare case of rubella that developed after rubella vaccine administration. A 54-year-old man complained of back and neck pain for some days. He presented with generalized rash and arthralgia that had persisted for two days before his visit. His [...] Read more.
We present an extremely rare case of rubella that developed after rubella vaccine administration. A 54-year-old man complained of back and neck pain for some days. He presented with generalized rash and arthralgia that had persisted for two days before his visit. His vital signs were normal, and arthralgia had disappeared during an examination, but lymphadenopathy in the left posterior neck and pink papules were observed throughout the body. He had received his first Rubella vaccination 17 days before this visit and had attended a crowded festival. Owing to the rubella epidemic in that prefecture, we performed a rubella antibody test and polymerase chain reaction assay using blood, urine, and pharyngeal swab specimens. Rubella IgG and IgM antibody titers were 3 and 1.48, respectively. The pharyngeal swab yielded positive results for the 1a vaccine strain. Therefore, he was diagnosed with rubella due to rubella vaccination. His symptoms improved eventually. His clinical course was uncomplicated. Symptoms resolved within one week without specific treatment. The vaccine rubella strain is not as highly infectious as wild-type rubella strains. If rubella symptoms appear after vaccination, it must be investigated whether these are vaccine-specific adverse reactions, wild-strain rubella onset, or other eruptive viral infections. Full article
(This article belongs to the Special Issue Vaccination Related Adverse Reaction)
Show Figures

Figure 1

Article
Melatonin as Immune Potentiator for Enhancing Subunit Vaccine Efficacy against Bovine Viral Diarrhea Virus
Vaccines 2021, 9(9), 1039; https://doi.org/10.3390/vaccines9091039 - 18 Sep 2021
Cited by 1 | Viewed by 1203
Abstract
Bovine viral diarrhea virus (BVDV) is a pathogen associated with substantial economic losses in the dairy cattle industry. Currently, there are no effective vaccines against BVDV. Melatonin (MT) has been shown to have anti-inflammatory and anti-viral properties, and the use of MF59 in [...] Read more.
Bovine viral diarrhea virus (BVDV) is a pathogen associated with substantial economic losses in the dairy cattle industry. Currently, there are no effective vaccines against BVDV. Melatonin (MT) has been shown to have anti-inflammatory and anti-viral properties, and the use of MF59 in vaccines significantly enhances vaccine efficiency. Here, MT and MF59 were added into the Erns-LTB vaccine. Subsequently, their inhibitory activity on the NF-κB signaling pathway in Mardin-Darby Bovine Kidney cells and the hippocampus was assessed using western blot and quantitative reverse transcription PCR. The findings revealed that MT in the Erns-LTB vaccine decreases the phosphorylation of p65 proteins caused by BVDV infection. In addition, MT decreased the mRNA levels of IL-1β and IL-6 in vitro, but increased the production of IFN-α, IFN-β, Mx1 in vitro, brain-derived neurotrophic factor, cyclic amp response element-binding protein, and the stem cell factor in vivo. Furthermore, treatment with Erns-LTB + MF59 + MT stimulated the production of T lymphocytes, alleviated pathological damage, decreased expressions of BVDV antigen, and tight junction proteins in mice. These findings imply that MT has potential for use in the Erns-LTB vaccine to inhibit BVDV infection and regulate the immune responses of T-cells by inhibiting the NF-κB signaling pathway. Full article
Show Figures

Figure 1

Article
Development of a Conserved Chimeric Vaccine for Induction of Strong Immune Response against Staphylococcus aureus Using Immunoinformatics Approaches
Vaccines 2021, 9(9), 1038; https://doi.org/10.3390/vaccines9091038 - 18 Sep 2021
Cited by 15 | Viewed by 2144
Abstract
Staphylococcus aureus is one of the most notorious Gram-positive bacteria with a very high mortality rate. The WHO has listed S. aureus as one of the ESKAPE pathogens requiring urgent research and development efforts to fight against it. Yet there is a major [...] Read more.
Staphylococcus aureus is one of the most notorious Gram-positive bacteria with a very high mortality rate. The WHO has listed S. aureus as one of the ESKAPE pathogens requiring urgent research and development efforts to fight against it. Yet there is a major layback in the advancement of effective vaccines against this multidrug-resistant pathogen. SdrD and SdrE proteins are attractive immunogen candidates as they are conserved among all the strains and contribute specifically to bacterial adherence to the host cells. Furthermore, these proteins are predicted to be highly antigenic and essential for pathogen survival. Therefore, in this study, using the immunoinformatics approach, a novel vaccine candidate was constructed using highly immunogenic conserved T-cell and B-cell epitopes along with specific linkers, adjuvants, and consequently modeled for docking with human Toll-like receptor 2. Additionally, physicochemical properties, secondary structure, disulphide engineering, and population coverage analysis were also analyzed for the vaccine. The constructed vaccine showed good results of worldwide population coverage and a promising immune response. For evaluation of the stability of the vaccine-TLR-2 docked complex, a molecular dynamics simulation was performed. The constructed vaccine was subjected to in silico immune simulations by C-ImmSim and Immune simulation significantly provided high levels of immunoglobulins, T-helper cells, T-cytotoxic cells, and INF-γ. Lastly, upon cloning, the vaccine protein was reverse transcribed into a DNA sequence and cloned into a pET28a (+) vector to ensure translational potency and microbial expression. The overall results of the study showed that the designed novel chimeric vaccine can simultaneously elicit humoral and cell-mediated immune responses and is a reliable construct for subsequent in vivo and in vitro studies against the pathogen. Full article
(This article belongs to the Special Issue Advances in Vaccine Development)
Show Figures

Figure 1

Article
Murine Dendritic Cells Grown in Serum-Free Culture Show Potent Therapeutic Activity when Loaded with Novel Th Epitopes in an Orthotopic Model of HER2pos Breast Cancer
Vaccines 2021, 9(9), 1037; https://doi.org/10.3390/vaccines9091037 - 18 Sep 2021
Viewed by 993
Abstract
Preferred methods for generating mouse dendritic cells (DC) would encompass qualities of consistency, high yield, and potent function. Serum-free culture is also highly desirable, since this is the standard for cell-based therapies used in humans. We report here a serum-free modification of a [...] Read more.
Preferred methods for generating mouse dendritic cells (DC) would encompass qualities of consistency, high yield, and potent function. Serum-free culture is also highly desirable, since this is the standard for cell-based therapies used in humans. We report here a serum-free modification of a culture method generating mature, activated DCs from bone marrow precursors. This is achieved through a two-stage culture comprised of 6-day expansion in Flt3 ligand and IL-6 followed by brief differentiation in a medium containing GM-CSF and IL-4, with subsequent activation using TLR ligands ODN1826 and LPS. The serum-free DCs achieve yields and surface phenotype including IL-12p70 secretion similar to standard serum-replete cultures, display a capacity to sensitize in vivo against both MHC class I- and Class II-restricted antigens, and exhibit some aspects of “killer DC” function against tumor cells. We used these DCs to help identify novel CD4pos Th epitopes on the rat ErbB2/HER-2 protein and demonstrated a subset of these as effective immunogens in a DC-based therapeutic model of HER-2pos breast cancer in Balb/c mice, where they induced powerful Th1-polarized immune responses. This method represents a useful way to efficiently produce large numbers of murine dendritic cells with excellent in vivo function well-suited for use in experimental vaccine studies. Full article
(This article belongs to the Section Cancer Vaccines and Immunotherapy)
Show Figures

Figure 1

Editorial
Advances in Vaccine Development
Vaccines 2021, 9(9), 1036; https://doi.org/10.3390/vaccines9091036 - 18 Sep 2021
Viewed by 1483
Abstract
The Special Issue titled “Advances in Vaccine Development” contains articles, reviews, and a perspective on advances in vaccine delivery and expression, nanovaccines, epitopes, proteins and adjuvants, and new vaccine platforms [...] Full article
(This article belongs to the Special Issue Advances in Vaccine Development)
Article
Uptake of Non-Mandatory Vaccinations in Future Physicians in Italy
Vaccines 2021, 9(9), 1035; https://doi.org/10.3390/vaccines9091035 - 17 Sep 2021
Cited by 1 | Viewed by 926
Abstract
In 2017 in Italy, a number of vaccinations became mandatory or started to be recommended and offered free of charge. In this study, we aimed at assessing the coverage rates for those vaccinations in the pre-mandatory era among students at the School of [...] Read more.
In 2017 in Italy, a number of vaccinations became mandatory or started to be recommended and offered free of charge. In this study, we aimed at assessing the coverage rates for those vaccinations in the pre-mandatory era among students at the School of Medicine of Padua University studying the degree course in medicine and surgery (future physicians) on the basis of the vaccination certificates presented during health surveillance. The vaccinations considered were those against pertussis, rubella, mumps, measles, varicella, Haemophilus influenzae type b (which became mandatory in 2017), pneumococcus, meningococcus C and meningococcus B (only suggested and offered for free since 2017). The study enrolled 4706 students of medicine and surgery. High vaccine uptake was observed, especially in younger students (born after 1990), with vaccines against pertussis, rubella, mumps and measles. Good completion for Haemophilus influenzae type b and meningococcus C was also observed. Very low coverage rates (all under 10%) for vaccination against varicella, pneumococcus and meningococcus B were observed. In conclusion, uptake for some non-mandatory vaccines was below the recommended threshold, although younger generations showed a higher uptake, possibly as a results of policy implemented at the national level. Our findings support the idea to consider health surveillance visits also as an additional opportunity to overcome confidence and convenience barriers and offer vaccine administration. Full article
Show Figures

Figure 1

Article
Oral Peptide Vaccine against Hookworm Infection: Correlation of Antibody Titers with Protective Efficacy
Vaccines 2021, 9(9), 1034; https://doi.org/10.3390/vaccines9091034 - 17 Sep 2021
Cited by 6 | Viewed by 2055
Abstract
Approximately 0.4 billion individuals worldwide are infected with hookworm. An effective vaccine is needed to not only improve the health of those affected and at high risk, but also to improve economic growth in disease-endemic areas. An ideal anti-hookworm therapeutic strategy for mass [...] Read more.
Approximately 0.4 billion individuals worldwide are infected with hookworm. An effective vaccine is needed to not only improve the health of those affected and at high risk, but also to improve economic growth in disease-endemic areas. An ideal anti-hookworm therapeutic strategy for mass administration is a stable and orally administered vaccine. Oral vaccines are advantageous as they negate the need for trained medical staff for administration and do not require strict sterility conditions. Vaccination, therefore, can be carried out at a significantly reduced cost. One of the most promising current antigenic targets for hookworm vaccine development is the aspartic protease digestive enzyme (APR-1). Antibody-mediated neutralization of APR-1 deprives the worm of nourishment, leading to reduced worm burdens in vaccinated hosts. Previously, we demonstrated that, when incorporated into vaccine delivery systems, the APR-1-derived p3 epitope (TSLIAGPKAQVEAIQKYIGAEL) was able to greatly reduce worm burdens (≥90%) in BALB/c mice; however, multiple, large doses of the vaccine were required. Here, we investigated a variety of p3-antigen conjugates to optimize antigen delivery and establish immune response/protective efficacy relationships. We synthesized, purified, and characterized four p3 peptide-based vaccine candidates with: (a) lipidic (lipid core peptide (LCP)); (b) classical polymeric (polymethylacrylate (PMA)); and (c) novel polymeric (polyleucine in a branched or linear arrangement, BL10 or LL10, respectively) groups as self-adjuvanting moieties. BL10 and LL10 induced the highest serum anti-p3 and anti-APR-1 IgG titers. Upon challenge with rodent hookworms, the highest significant reduction in worm burden was observed in mice immunized with LL10. APR-1-specific serum IgG titers correlated with worm burden reduction. Thus, we provide the first vaccine-triggered immune response-protection relationship for hookworm infection. Full article
(This article belongs to the Special Issue Vaccines Development in Australia)
Show Figures

Figure 1

Review
Challenges of Storage and Stability of mRNA-Based COVID-19 Vaccines
Vaccines 2021, 9(9), 1033; https://doi.org/10.3390/vaccines9091033 - 17 Sep 2021
Cited by 50 | Viewed by 8252
Abstract
In December 2019, a new and highly pathogenic coronavirus emerged—coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), quickly spread throughout the world. In response to this global pandemic, a few vaccines were allowed for emergency use, beginning [...] Read more.
In December 2019, a new and highly pathogenic coronavirus emerged—coronavirus disease 2019 (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), quickly spread throughout the world. In response to this global pandemic, a few vaccines were allowed for emergency use, beginning in November 2020, of which the mRNA-based vaccines by Moderna (Moderna, Cambridge, MA, USA) and BioNTech (BioTech, Mainz, Germany)/Pfizer (Pfizer, New York, NY, USA) have been identified as the most effective ones. The mRNA platform allowed rapid development of vaccines, but their global use is limited by ultracold storage requirements. Most resource-poor countries do not have cold chain storage to execute mass vaccination. Therefore, determining strategies to increase stability of mRNA-based vaccines in relatively higher temperatures can be a game changer to address the current global pandemic and upcoming new waves. In this review, we summarized the current research strategies to enhance stability of the RNA vaccine delivery system. Full article
(This article belongs to the Special Issue Novel Vaccine Stabilization and Delivery Technologies)
Review
An Overview of Influenza Viruses and Vaccines
Vaccines 2021, 9(9), 1032; https://doi.org/10.3390/vaccines9091032 - 17 Sep 2021
Cited by 17 | Viewed by 7003
Abstract
Influenza remains one of the major public health concerns because it causes annual epidemics and can potentially instigate a global pandemic. Numerous countermeasures, including vaccines and antiviral treatments, are in use against seasonal influenza infection; however, their effectiveness has always been discussed due [...] Read more.
Influenza remains one of the major public health concerns because it causes annual epidemics and can potentially instigate a global pandemic. Numerous countermeasures, including vaccines and antiviral treatments, are in use against seasonal influenza infection; however, their effectiveness has always been discussed due to the ongoing resistance to antivirals and relatively low and unpredictable efficiency of influenza vaccines compared to other vaccines. The growing interest in vaccines as a promising approach to prevent and control influenza may provide alternative vaccine development options with potentially increased efficiency. In addition to currently available inactivated, live-attenuated, and recombinant influenza vaccines on the market, novel platforms such as virus-like particles (VLPs) and nanoparticles, and new vaccine formulations are presently being explored. These platforms provide the opportunity to design influenza vaccines with improved properties to maximize quality, efficacy, and safety. The influenza vaccine manufacturing process is also moving forward with advancements relating to egg- and cell-based production, purification processes, and studies into the physicochemical attributes and vaccine degradation pathways. These will contribute to the design of more stable, optimized vaccine formulations guided by contemporary analytical testing methods and via the implementation of the latest advances in the field. Full article
(This article belongs to the Special Issue Advances in Vaccine Development)
Show Figures

Figure 1

Article
Prospective Cohort Study of the Kinetics of Specific Antibodies to SARS-CoV-2 Infection and to Four SARS-CoV-2 Vaccines Available in Serbia, and Vaccine Effectiveness: A 3-Month Interim Report
Vaccines 2021, 9(9), 1031; https://doi.org/10.3390/vaccines9091031 - 17 Sep 2021
Cited by 8 | Viewed by 9129
Abstract
Real-life data on the performance of vaccines against SARS-CoV-2 are still limited. We here present the rates of detection and levels of antibodies specific for the SARS-CoV-2 spike protein RBD (receptor binding domain) elicited by four vaccines available in Serbia, including BNT-162b2 (BioNTech/Pfizer), [...] Read more.
Real-life data on the performance of vaccines against SARS-CoV-2 are still limited. We here present the rates of detection and levels of antibodies specific for the SARS-CoV-2 spike protein RBD (receptor binding domain) elicited by four vaccines available in Serbia, including BNT-162b2 (BioNTech/Pfizer), BBIBP-CorV (Sinopharm), Gam-COVID-Vac (Gamaleya Research Institute) and ChAdOx1-S (AstraZeneca), compared with those after documented COVID-19, at 6 weeks and 3 months post first vaccine dose or post-infection. Six weeks post first vaccine dose, specific IgG antibodies were detected in 100% of individuals fully vaccinated with BNT-162b2 (n = 100) and Gam-COVID-Vac (n = 12) and in 81.7% of BBIBP-CorV recipients (n = 148), while one dose of ChAdOx1-S (n = 24) induced specific antibodies in 75%. Antibody levels elicited by BNT-162b2 were higher, while those elicited by BBIBP-CorV were lower, than after SARS-CoV-2 infection. By 3 months post-vaccination, antibody levels decreased but remained ≥20-fold above the cut-off in BNT-162b2 but not in BBIBP-CorV recipients, when an additional 30% were seronegative. For all vaccines, antibody levels were higher in individuals with past COVID-19 than in naïve individuals. A total of twelve new infections occurred within the first 3 months post-vaccination, eight after the first dose of BNT-162b2 and ChAdOx1-S (one each) and BBIBP-CorV (six), and four after full vaccination with BBIBP-CorV, but none required hospitalization. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
Show Figures

Figure 1

Review
A Review of Australian Tick Vaccine Research
Vaccines 2021, 9(9), 1030; https://doi.org/10.3390/vaccines9091030 - 16 Sep 2021
Cited by 3 | Viewed by 1747
Abstract
Tick vaccine research in Australia has demonstrated leadership worldwide through the development of the first anti-tick vaccine in the 1990s. Australia’s Commonwealth Scientific and Industrial Research Organisation’s (CSIRO) research led to the development of vaccines and/or precursors of vaccines (such as crude extracts) [...] Read more.
Tick vaccine research in Australia has demonstrated leadership worldwide through the development of the first anti-tick vaccine in the 1990s. Australia’s Commonwealth Scientific and Industrial Research Organisation’s (CSIRO) research led to the development of vaccines and/or precursors of vaccines (such as crude extracts) for both the cattle tick and the paralysis tick. CSIRO commercialised the Bm86 vaccine in the early 1990s for Rhipicephalus australis; however, issues with dosing and lack of global conservation led to the market closure of Tick-GARD in Australia. New research programs arose both locally and globally. The Australian paralysis tick Ixodes holocyclus has perplexed research veterinarians since the 1920s; however, not until the 2000s did biotechnology exist to elucidate the neurotoxin—holocyclotoxin family of toxins leading to a proof of concept vaccine cocktail. This review revisits these discoveries and describes tributes to deceased tick vaccine protagonists in Australia, including Sir Clunies Ross, Dr Bernard Stone and Dr David Kemp. Full article
(This article belongs to the Special Issue Vaccines Development in Australia)
Article
“Vaccinate, Do Not Hesitate!”. Vaccination Readiness against COVID-19 among Polish Nursing Undergraduate Students: A National Cross-Sectional Survey
Vaccines 2021, 9(9), 1029; https://doi.org/10.3390/vaccines9091029 - 16 Sep 2021
Cited by 9 | Viewed by 2425
Abstract
COVID-19 vaccination raises numerous concerns among the public, and also among medical personnel including nurses. As nurses play a crucial role in the process of vaccination, it is important to recognize the attitudes of students of nursing, nurses in spe, toward COVID-19 vaccination, [...] Read more.
COVID-19 vaccination raises numerous concerns among the public, and also among medical personnel including nurses. As nurses play a crucial role in the process of vaccination, it is important to recognize the attitudes of students of nursing, nurses in spe, toward COVID-19 vaccination, as well as to define the factors influencing students’ pro-vaccine choices. The study was conducted between March and April 2021 at all medical universities in Poland educating nurses in spe. The study included 793 first-degree students from 12 universities. The results revealed that the vast majority of students of nursing (77.2%) were vaccinated against COVID-19, as 61.2% received an mRNA vaccine and 16% a viral vector vaccine. Every other person in the non-vaccinated group declared their intention to get a vaccination. A trend was observed whereby people co-living with persons from the risk group, who are at risk of a severe form of COVID-19, showed greater willingness to get a vaccine. The study results identified the role of universities in increasing the vaccination rate among students, both in terms of education about vaccinations and in shaping pro-vaccine attitudes among students, as well as organizing vaccinations on university campuses to facilitate the process. Full article
(This article belongs to the Special Issue Vaccination and Public Health Version II: COVID-19 Vaccination)
Show Figures

Figure 1

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 7 | Viewed by 1983
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
(This article belongs to the Collection COVID-19 Vaccines and Vaccination)
Show Figures

Figure 1

Article
N-2-Hydroxypropyl Trimethyl Ammonium Chloride Chitosan as Adjuvant Enhances the Immunogenicity of a VP2 Subunit Vaccine against Porcine Parvovirus Infection in Sows
Vaccines 2021, 9(9), 1027; https://doi.org/10.3390/vaccines9091027 - 16 Sep 2021
Cited by 2 | Viewed by 1358
Abstract
Porcine parvovirus (PPV) is the most important infectious agent causing infertility in pigs, which can be prevented by routine vaccination. Successful vaccination depends on the association with potent adjuvants that can enhance the immunogenicity of antigen and activate the immune system. Polysaccharide adjuvant [...] Read more.
Porcine parvovirus (PPV) is the most important infectious agent causing infertility in pigs, which can be prevented by routine vaccination. Successful vaccination depends on the association with potent adjuvants that can enhance the immunogenicity of antigen and activate the immune system. Polysaccharide adjuvant has low toxicity and high safety, and they can enhance the humoral, cellular and mucosal immune responses. In the present study, we prepared the VP2 protein subunit vaccine against PPV (PPV/VP2/N-2-HACC) using water-soluble N-2-Hydroxypropyl trimethyl ammonium chloride chitosan (N-2-HACC) as the vaccine adjuvant, and the ability of the PPV/VP2/N-2-HACC to induce immune responses and protect sows from PPV infection was evaluated. In vivo immunization showed that the sows immunized with the PPV/VP2/N-2-HACC by intramuscular injection produced higher HI antibody levels and long-term immune protection compared with the other groups, while the subunit vaccine did not stimulate the proliferation of CD4+ and CD8+ T lymphocytes to trigger the secretion of higher levels of IL-2, IL-4, IFN-α, IFN-β, and IFN-γ, indicating that the PPV/VP2/N-2-HACC mainly induced humoral immunity rather than cellular immunity. PPV was not detected in the viscera of the sows immunized with the PPV/VP2/N-2-HACC, and the protective efficacy was 100%. Collectively, our findings suggested that the N-2-HACC was a potential candidate adjuvant, and the PPV/VP2/N-2-HACC had immense application value for the control of PPV. Full article
(This article belongs to the Section Veterinary Vaccines)
Show Figures

Figure 1

Review
Current Status of HIV-1 Vaccines
Vaccines 2021, 9(9), 1026; https://doi.org/10.3390/vaccines9091026 - 16 Sep 2021
Cited by 8 | Viewed by 3251
Abstract
HIV-1 infection and its progression to AIDS remains a significant global health challenge, particularly for low-income countries. Developing a vaccine to prevent HIV-1 infections has proven to be immensely challenging with complex biological acquisition and infection, unforeseen clinical trial disappointments, and funding issues. [...] Read more.
HIV-1 infection and its progression to AIDS remains a significant global health challenge, particularly for low-income countries. Developing a vaccine to prevent HIV-1 infections has proven to be immensely challenging with complex biological acquisition and infection, unforeseen clinical trial disappointments, and funding issues. This paper discusses important landmarks of progress in HIV-1 vaccine development, various vaccine strategies, and clinical trials. Full article
(This article belongs to the Special Issue Advances in Plasmid DNA and mRNA as Vaccine Technologies)
Article
Multicomponent Vaccines against Group A Streptococcus Can Effectively Target Broad Disease Presentations
Vaccines 2021, 9(9), 1025; https://doi.org/10.3390/vaccines9091025 - 15 Sep 2021
Viewed by 1279
Abstract
Group A Streptococcus (GAS) is an important global human pathogen, with a wide range of disease presentations, from mild mucosal infections like pharyngitis to invasive diseases such as toxic shock syndrome. The effect on health and mortality from GAS infections is substantial worldwide, [...] Read more.
Group A Streptococcus (GAS) is an important global human pathogen, with a wide range of disease presentations, from mild mucosal infections like pharyngitis to invasive diseases such as toxic shock syndrome. The effect on health and mortality from GAS infections is substantial worldwide, particularly from autoimmune sequelae-like rheumatic heart disease (RHD), and there is currently no licenced vaccine. We investigated protein antigens targeting a broad range of GAS disease presentations as vaccine components in individual and combination formulations. The potency and functional immunity generated were evaluated and compared between groups. Antibodies against all components were found in pooled human IgG (IVIG) and an immune response generated following the subcutaneous immunisation of mice. A combination immunisation showed a reduction in IgG response for SpyCEP but an increase for Cpa and Mac-1 (IdeS). An opsonophagocytosis assay (OPA) showed the killing of GAS with immune sera against M protein and combination groups, with a lower killing activity observed for immune sera against other individual antigens. Specific antigen assays showed functional immunity against SpyCEP and Mac-1 from both individual and combination immunisations, with the activity correlating with antibody titres. However, efficient blocking of the binding activity of Cpa to collagen I and fibronectin could not be demonstrated with immune sera or purified IgG. Our data indicate that combination immunisations, while effective at covering a broader range of virulence factors, can also affect the immune response generated. Further, our results showed that an OPA alone is inadequate for understanding protection from vaccination, particularly when considering protection from immune evasion factors and evaluation of the colonisation leading to pharyngitis. Full article
(This article belongs to the Special Issue Bacterial Carbohydrate and Protein Vaccine Research)
Show Figures

Figure 1

Review
COVID-19 Vaccine Donations—Vaccine Empathy or Vaccine Diplomacy? A Narrative Literature Review
Vaccines 2021, 9(9), 1024; https://doi.org/10.3390/vaccines9091024 - 15 Sep 2021
Cited by 32 | Viewed by 6872
Abstract
Introduction: Vaccine inequality inflames the COVID-19 pandemic. Ensuring equitable immunization, vaccine empathy is needed to boost vaccine donations among capable countries. However, damaging narratives built around vaccine donations such as “vaccine diplomacy” could undermine nations’ willingness to donate their vaccines, which, in turn, [...] Read more.
Introduction: Vaccine inequality inflames the COVID-19 pandemic. Ensuring equitable immunization, vaccine empathy is needed to boost vaccine donations among capable countries. However, damaging narratives built around vaccine donations such as “vaccine diplomacy” could undermine nations’ willingness to donate their vaccines, which, in turn, further exacerbate global vaccine inequality. However, while discussions on vaccine diplomacy are on the rise, there is limited research related to vaccine diplomacy, especially in terms of its characteristics and effects on vaccine distribution vis-à-vis vaccine empathy. Thus, to bridge the research gap, this study aims to examine the defining attributes of vaccine diplomacy and its potential effects on COVID-19 immunization, particularly in light of vaccine empathy. Methods: A narrative review was conducted to shed light on vaccine diplomacy’s defining attributes and effects in the context of COVID-19 vaccine distribution and dissemination. Databases such as PubMed and Medline were utilized for literature search. Additionally, to ensure up-to-date insights are included in the review, validated reports and reverse tracing of eligible articles’ reference lists in Google Scholar have also been conducted to locate relevant records. Results: Vaccine empathy is an individual or a nation’s capability to sympathize with other individuals or nations’ vaccine wants and needs, whereas vaccine diplomacy is a nation’s vaccine efforts that aim to build mutually beneficial relationships with other nations ultimately. Our findings show that while both vaccine empathy and vaccine diplomacy have their strengths and weaknesses, they all have great potential to improve vaccine equality, particularly amid fast-developing and ever-evolving global health crises such as COVID-19. Furthermore, analyses show that, compared to vaccine empathy, vaccine diplomacy might be a more sustainable solution to improve vaccine donations mainly because of its deeper and stronger roots in multilateral collaboration and cooperation. Conclusion: Similar to penicillin, automated external defibrillators, or safety belts amid a roaring global health disaster, COVID-19 vaccines are, essentially, life-saving consumer health products that should be available to those who need them. Though man-made and complicated, vaccine inequality is nonetheless a solvable issue—gaps in vaccine distribution and dissemination can be effectively addressed by timely vaccine donations. Overall, our study underscores the instrumental and indispensable role of vaccine diplomacy in addressing the vaccine inequality issue amid the COVID-19 pandemic and its potentials for making even greater contributions in forging global solidarity amid international health emergencies. Future research could investigate approaches that could further inspire and improve vaccine donations among capable nations at a global scale to advance vaccine equity further. Full article
(This article belongs to the Special Issue Vaccines: Uptake and Equity in Times of the COVID-19 Pandemic)
Show Figures

Figure 1

Article
Vaccine Hesitancy and Refusal: Behavioral Evidence from Rural Northern Nigeria
Vaccines 2021, 9(9), 1023; https://doi.org/10.3390/vaccines9091023 - 14 Sep 2021
Cited by 2 | Viewed by 2124
Abstract
It is widely believed that vaccine hesitancy is prevalent in African countries, although this belief is without rigorous evidence. Our field experiment in rural northern Nigeria behaviorally measured the prevalence of vaccine hesitancy—the non-uptake of vaccines despite their availability due to non-monetary factors [...] Read more.
It is widely believed that vaccine hesitancy is prevalent in African countries, although this belief is without rigorous evidence. Our field experiment in rural northern Nigeria behaviorally measured the prevalence of vaccine hesitancy—the non-uptake of vaccines despite their availability due to non-monetary factors directly associated with vaccination. We randomly assigned two tasks to women: answering a short survey at their house vs. additionally receiving a free tetanus vaccine by submitting a voucher. The differences in their completion rates captured vaccine hesitancy, showing the rate to be about 13%. Our study reveals that absolute refusers with negative willingness to pay (WTP) for vaccines, who are likely to have strong misperceptions or a distrust of vaccines, account for about half of vaccine hesitaters, while floating refusers with zero or weakly positive WTP, who are likely to be indifferent about vaccines, account for the other half. A simple intervention, such as a door-to-door vaccination campaign, is likely to be effective for floating refusers, while interventions for absolute refusers need to effectively change their misperceptions or distrust of vaccines. Full article
Show Figures

Figure 1

Brief Report
Reporting of Acute Inflammatory Neuropathies with COVID-19 Vaccines: Subgroup Disproportionality Analyses in VigiBase
Vaccines 2021, 9(9), 1022; https://doi.org/10.3390/vaccines9091022 - 14 Sep 2021
Cited by 10 | Viewed by 4962
Abstract
Since marketing authorization, cases of neuralgic amyotrophy (NA), facial paralysis/Bell’s palsy (FP/BP), and Guillain-Barré syndrome (GBS) were reported with COVID-19 vaccines of different technologies. This study aimed to assess whether NA, FP/BP, and GBS were more frequently reported in VigiBase with COVID-19 vaccines [...] Read more.
Since marketing authorization, cases of neuralgic amyotrophy (NA), facial paralysis/Bell’s palsy (FP/BP), and Guillain-Barré syndrome (GBS) were reported with COVID-19 vaccines of different technologies. This study aimed to assess whether NA, FP/BP, and GBS were more frequently reported in VigiBase with COVID-19 vaccines (of any technologies) than with other viral vaccines, over the full database and across potential risk groups by sex and age. The reporting odds ratio (ROR) with 95% confidence interval (95% CI) was used as the measure of disproportionality and subgroup disproportionality analyses were performed by sex and age. Out of 808,906 safety reports with COVID-19 vaccines, 57 (0.01%) reported NA, 3320 (0.4%) FP/BP, and 632 (0.1%) GBS. There were not signals of disproportionate reporting for NA and GBS with COVID-19 vaccines against other viral vaccines. FP/BP was disproportionately more frequently reported with COVID-19 vaccines than with other viral vaccines over the full database (ROR 1.12, 95%CI 1.07–1.17), in males (ROR 1.65, 95%CI 1.54–1.78) and in age subgroups 65–74 years (ROR 1.21, 95%CI 1.05–1.39) and ≥75 years (ROR 1.84, 95%CI 1.52–2.22). Albeit not proving causation, these findings might support clinicians in decision-making for patients potentially at risk for developing an acute inflammatory neuropathy with COVID-19 vaccines. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
Review
Recent and Future Advances in the Chemoenzymatic Synthesis of Homogeneous Glycans for Bacterial Glycoconjugate Vaccine Development
Vaccines 2021, 9(9), 1021; https://doi.org/10.3390/vaccines9091021 - 14 Sep 2021
Cited by 2 | Viewed by 1546
Abstract
Vaccines are important in preventing disease outbreaks and controlling the spread of disease in a population. A variety of vaccines exist, including subunit, recombinant, and conjugate vaccines. Glycoconjugate vaccines have been an important tool to fight against diseases caused by a number of [...] Read more.
Vaccines are important in preventing disease outbreaks and controlling the spread of disease in a population. A variety of vaccines exist, including subunit, recombinant, and conjugate vaccines. Glycoconjugate vaccines have been an important tool to fight against diseases caused by a number of bacteria. Glycoconjugate vaccines are often heterogeneous. Vaccines of the future are becoming more rationally designed to have a defined oligosaccharide chain length and position of conjugation. Homogenous vaccines could play an important role in assessing the relationship between vaccine structure and immune response. This review focuses on recent advances in the chemoenzymatic production of defined bacterial oligosaccharides for vaccine development with a focus on Neisseria meningitidis and selected WHO-prioritized antibacterial resistant-pathogens. We also provide some perspective on future advances in the chemoenzymatic synthesis of well-defined oligosaccharides. Full article
Show Figures

Figure 1

Article
Evaluation of Four Commercial Vaccines for the Protection of Piglets against the Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus (hp-PRRSV) QH-08 Strain
Vaccines 2021, 9(9), 1020; https://doi.org/10.3390/vaccines9091020 - 14 Sep 2021
Cited by 3 | Viewed by 1234
Abstract
Vaccination is the best way to prevent economic losses from highly pathogenic porcine reproductive and respiratory syndrome virus (hp-PRRSV) disease. However, the commercially available vaccines need to periodically evaluate their efficacy against infections caused by new hp-PRRSV variants. Therefore, the objective of this [...] Read more.
Vaccination is the best way to prevent economic losses from highly pathogenic porcine reproductive and respiratory syndrome virus (hp-PRRSV) disease. However, the commercially available vaccines need to periodically evaluate their efficacy against infections caused by new hp-PRRSV variants. Therefore, the objective of this study was to evaluate the efficacy of four (two modified live vaccines (MLV) and two inactivated) PRRSV commercial vaccines in piglets challenged with QH-08 and to estimate the genetic distance of the vaccine strains from recently isolated (QH-08) filed strain. Randomly, piglets (n = 5) allocated in groups 1–4 were immunized with Ingelvac PRRS MLV, CH-1a, JXA1, and JXA1-RMLV vaccines, whereas the infected and non-infected control piglets in groups 5 and 6 (n = 3), respectively, were subjected to PBS. Results indicated that JXA1 and JXA1-R MLV vaccines showed complete protection, but Ingelvac PRRS MLV and CH-1α vaccines revealed partial protection against the QH-08 PRRSV challenge. Similarly, vaccinated and challenged pigs showed lower macroscopic and microscopic lesions than the pigs in group 5. Our findings demonstrated a new insight that the variation in ORF1a and 1b coding sequence could significantly affect PRRSV vaccines efficacy. In conclusion, QH-08 is a good candidate for the design and development of an innovative PRRSV vaccine that ultimately helps in the control and prevention strategies. Full article
(This article belongs to the Special Issue PRRSV Vaccinology and Immunology)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop