Search Results (156)

Background: Chronic cytomegalovirus (CMV) infection may favor the development of immunosenescence and inflammation that impair vaccine responses, including COVID-19. In addition, the polymorphism of the interferon-lambda gene (IFNλ) affects COVID-19 immune responses in older adults. Objective: We aimed to investigate the impact of IFNλ polymorphism (IL28B gene-rs12979860) on the immune/inflammatory response to vaccination with CoronaVac for COVID-19 in older adults who were CMV-seropositive. Methods: Blood samples from 42 CMV-seropositive older adults (73.7 ± 4.5 years) were collected before and 30 days after immunization with a second dose of the CoronaVac vaccine to evaluate the immune/inflammatory response. Results: At genotyping, 20 subjects were homozygous for the C/C alleles (Allele-1 group), 5 were homozygous for the T/T Alleles (Allele-2 group), and 17 were heterozygous (C/T, Alleles-1/2 group). The Allele-1 group showed higher IgG levels for COVID-19 (p = 0.0269) and intermediate monocyte percentage (p = 0.017), in contrast to a lower non-classical monocyte percentage (p = 0.0141) post-vaccination than pre-vaccination. Also, this group showed that IgG levels for CMV were positively associated with a systemic pro-inflammatory state and senescent T cells (CD4+ and CD8+). The Allele-2 group presented higher IFN-β levels at pre- (p = 0.0248) and post-vaccination (p = 0.0206) than the values in the Allele-1 and Alleles-1/2 groups, respectively. In addition, the Allele-2 and Alleles-1/2 groups showed that IgG levels for COVID-19 were positively associated with a balanced systemic inflammatory state. Conclusion: CMV-seropositivity in older adults who had Allele-1 could lead to an unbalanced systemic inflammatory state, which may impair their antibody response to COVID-19 vaccination compared to other volunteer groups. Full article

Background: Allogeneic hematopoietic stem cell transplant (Allo-HSCT) recipients are still at increased risk of severe COVID-19 infection. Vaccination is a critical strategy to protect this population. This real-world prospective cohort study aimed to evaluate the immune response and clinical outcomes of COVID-19 vaccines in Allo-HSCT recipients. Methods: Allo-HSCT recipients (median age: 48 years) who received either the BNT162b2 or CoronaVac vaccines were included. Antibodies against the SARS-CoV-2 spike protein were quantitatively measured using the chemiluminescent microparticle immunoassay. Patient- and vaccine-related factors affecting antibody responses were analyzed. Adverse events, including graft-versus-host disease (GVHD) and post-vaccine infections, were recorded. Results: Among 95 Allo-HSCT recipients, 86.3% achieved adequate antibody responses following COVID-19 vaccination. Patients receiving ≥3 vaccine doses showed significantly higher antibody titers compared to those with only 2 doses (OR: 0.11; 95% CI: 0.02–0.53; p = 0.006 **). The use of Ruxolitinib or Ibrutinib was associate with increased odds of low antibody response (OR: 38.39; 95% CI: 3.14–468.95; p = 0.004 **). Hypogammaglobulinemia (low serum IgG levels) was associated with a reduced antibody response (OR: 0.17; 95% CI: 0.03–0.96; p = 0.045 *), while no significant correlation was found between serum IgA levels and antibody responses (p = 0.672). Three cases of post-vaccine GVHD were observed, and no fatalities related to COVID-19 occurred during the study. Conclusions: COVID-19 vaccination is safe and effective in Allo-HSCT recipients, with stronger responses especially following ≥3 vaccine doses. Patients receiving GVHD treatment or with hypogammaglobulinemia exhibited impaired responses, emphasizing the need for tailored vaccination strategies and close monitoring in this population. Full article

Background/Objectives: COVID-19 has been associated with a wide range of immune responses, including the production of autoantibodies, particularly in severe cases. This study investigates the IgG autoantibody responses in patients with varying severities of COVID-19 infection and compares these responses with vaccinated individuals. Methods: We utilized proteomic profiling to analyze autoantibody reactivity against a broad spectrum of proteins expressed in lymphoid and myeloid cell subsets in serum samples from severe and moderate COVID-19 patients, as well as vaccinated individuals who received the inactivated CoronaVac (Sinovac) vaccine. Results: Our findings indicate a marked increase in the diversity and number of IgG autoantibodies targeting intracellular and membrane-associated proteins in severe COVID-19 cases, compared to those with moderate cases of the disease. The autoantibody response in severe cases was found to primarily target proteins involved in immune cell activation, signaling, and differentiation, suggesting potential pathways of immune dysregulation and autoimmunity. In contrast, vaccinated individuals did not exhibit similar autoantibody reactivity, pointing to a more controlled immune response post-vaccination. Notably, no significant autoimmune responses were detected in the vaccinated cohort, suggesting that the inactivated vaccine does not induce autoreactive IgG. These findings align with the established safety profile of COVID-19 vaccines, especially in comparison to the heightened immune dysregulation observed in severe COVID-19 patients. The absence of a significant autoantibody response in vaccinated individuals supports the notion that vaccines, while inducing robust immune activation, do not typically trigger autoimmunity in healthy individuals. Conclusions: Our study underscores the importance of distinguishing between the immune responses triggered by infection and vaccination and highlights the need for the continued monitoring of autoimmune responses in severe COVID-19 cases. Future research should focus on the long-term persistence and clinical relevance of these autoantibodies, particularly in individuals with pre-existing autoimmune conditions or genetic predispositions. Full article

SARS-CoV-2 has caused global disruptions, prompting studies on immune responses to COVID-19 vaccines, particularly antibodies against the Spike (S) protein. However, responses to the Nucleocapsid (N) protein remain less explored. This study evaluated whether CoronaVac induces anti-N antibodies, and analyzed antibody dynamics after a BNT162b2 booster, given that CoronaVac targets both S and N proteins, while BNT162b2 targets only the S protein. Serum samples were collected at multiple intervals post-vaccination. The percentage of participants with positive anti-N antibodies increased from 40.26% to 62.09% after two doses of CoronaVac, but declined over time, reaching 29.07% and 18.87% after the second and third doses, respectively. However, seropositivity rose to 43.48% three months after the booster. Anti-S antibody levels peaked at 31,394 AU/mL after the booster, compared to 723.4 AU/mL after the first dose. These findings indicate that CoronaVac stimulates antibody responses against both S and N proteins. Monitoring antibody dynamics is crucial for optimizing vaccination strategies, particularly for high-risk populations, to help control COVID-19. Full article

Background: The COVID-19 pandemic has spurred a global race for a preventive vaccine, with a few becoming available just one year after describing this novel coronavirus disease. Among these are inactivated virus vaccines like CoronaVac (Sinovac Biotech), which are used in several countries to reduce the pandemic’s effects. However, its use was associated with low protection, particularly against novel virus variants that quickly appeared in the following months. Vaccines play a crucial role in activating the immune system to combat infections, with Memory B-cells being a key part of this mechanism, eliciting protective neutralizing antibodies. This work focused on studying B-cell memory repertoire after two consecutive doses of CoronaVac. Methodology: Memory B-cells were isolated from five CoronaVac vaccinated and five pre-pandemic individuals and subsequently stimulated in vitro before high-throughput Illumina sequencing of the Heavy Chain Variable repertoire. Results: We observed a shift in the VH repertoire with increased HCDR3 length and enrichment of IGVH 3-23, 3-30, 3-7, 3-72, and 3-74 for IgA BCRs and IGHV 4-39 and 4-59 for IgG BCRs. A high expansion of IgA-specific clonal populations was observed in vaccinated individuals relative to pre-pandemic controls, accompanied by shared IgA variable heavy chain (VH) sequences among memory B cells across different vaccine recipients of IgA clones was also observed in vaccinated individuals compared to pre-pandemic controls, with several IgA VH sharing between memory B cells from different vaccines. Moreover, a high convergence was observed among vaccinees and SARS-CoV-2 neutralizing antibody sequences found in the CoV-abDab database. Conclusion: These data show the ability of CoronaVac to elicit antibodies with characteristics similar to those previously identified as neutralizing antibodies, supporting its protective efficacy. Furthermore, this analysis of the immunological repertoire in the context of viral infections reinforces the importance of immunization in generating convergent antibodies for the antiviral response. Full article

Background: Few reports exist regarding the incidence and factors associated with allergic reactions to COVID-19 vaccines during post-marketing surveillance, especially for inactivated whole virus or viral vector vaccines. We aimed to determine the incidence and factors associated with self-reported allergic reactions to COVID-19 vaccines in the Thai population. Methods: A cross-sectional case-control study was conducted via telephone-based interviews. Cases were defined as physician-confirmed, self-reported vaccine recipients diagnosed with non-severe immediate allergic reactions, anaphylaxis, or delayed allergic reactions. Controls were randomly sampled from vaccinated individuals who reported no adverse events and were matched by the type of vaccine (1 case:2 controls). Demographic information and the history of atopic diseases were collected in both groups. Conditional logistic regression analysis was used to explore associated factors. Results: Among 215,079 vaccine doses administered, the incidence of self-reported skin symptoms of allergic reactions was 1821 events (0.85%). The risk factors for allergic reactions included age < 60 years (aOR 3.53; 95% CI:1.43–8.70; p = 0.006), female sex (aOR 8.33; 95% CI: 4.35–15.94; p < 0.001), a personal history of allergic rhinitis (aOR 4.32; 95% CI: 2.43–7.69; p < 0.001), atopic dermatitis (aOR 4.27; 95% CI: 1.74–10.47; p = 0.002), food allergies (aOR 6.53; 95% CI: 2.42–17.61; p < 0.001), and a family history of allergic disease (aOR 2.14; 95% CI: 1.12–4.08; p = 0.021). Conclusions: COVID-19 vaccines showed a low incidence of self-reported allergic reactions, which were more likely to occur in younger individuals, females, and those with a history of atopic diseases. Full article

Background/Objectives: Metabolic syndrome (MetS) is a predisposing factor for severe COVID-19. The effectiveness of COVID-19 vaccines in patients with MetS has been poorly investigated. The aim of this study was to evaluate the effectiveness of COVID-19 vaccination before (BO) and after the Omicron (AO) SARS-CoV-2 variant in patients with MetS. Methods: This retrospective observational study was carried out in a total of 3194 patients with MetS and a COVID-19 PCR or rapid antigen test. The main outcomes were vaccine effectiveness against infection, hospitalization and death resulting from COVID-19. Results: BO, only two doses of BNT162b2 were effective against infection, this effectiveness was lost AO. Also, with two doses, BNT162b2, ChAdOx1 and CoronaVac were effective against hospitalization BO; however, AO, only BNT162b2 and CoronaVac were effective. Regarding death as an outcome of COVID-19, two doses of BNT162b2 were effective BO, whereas AO, BNT162b2 and CoronaVac were 100% effective. BO the presentation of a sore throat increased after two doses of COVID-19 vaccine regardless of the type, and the presentation of dyspnea diminished after two doses of BNT162b2 and CoronaVac. Conclusions: The SARS-CoV-2 Omicron variant has impacted vaccines’ effectiveness against hospitalization and death in patients with MetS. A tailored vaccination scheme for patients with MetS should be implemented due to the varying effectiveness rates observed in our study. Full article

Maintenance hemodialysis patients are at increased risk of cardiovascular complications and mortality following COVID-19 infection due to compromised immune function. This study aims to evaluate the impact of the COVID-19 vaccine (CoronaVac) on cardiac function and survival in this population. Background/Objectives: We aimed to examine whether CoronaVac vaccination affects heart function and survival rates in maintenance hemodialysis patients. Specifically, we assessed changes in heart ultrasound (echocardiographic) measurements, B-type natriuretic peptide (BNP) levels, and survival outcomes by comparing vaccinated and unvaccinated patients. Methods: A retrospective analysis was conducted on 531 maintenance hemodialysis patients, including 79 who received CoronaVac and 452 who did not. We compared the pre- and post-infection changes in heart function (echocardiographic parameters) and BNP levels between the two groups and assessed their association with the survival rates. Results: The vaccinated patients were younger (60.54  ±  13.51 vs. 65.21  ±  13.76 years, p = 0.006) and had shorter dialysis durations (56.04  ±  51.88 vs. 73.73  ±  64.79 months, p = 0.022). The mortality rate was also significantly lower in the vaccinated group (6.33% vs. 14.38%, p = 0.049). After infection, the unvaccinated patients showed significant declines in heart function and increased B-type natriuretic peptide levels, while the vaccinated patients demonstrated no significant deterioration. Older age, coronary artery disease, inflammation levels, and heart abnormalities were identified as the key risk factors for mortality. Conclusions: CoronaVac was linked to lower mortality and better heart function in maintenance hemodialysis patients. The vaccine may help to reduce infection severity, lower strain on the heart, and improve the overall prognosis. Full article

Background: Despite adverse events following immunization (AEFI) being well described in vaccine trials, there is a need to produce more real-world data on events supposedly attributed to vaccination against COVID-19. This study aims to estimate the prevalence of AEFI in the first dose of COVID-19 vaccines in the state of Brazil and to verify whether such events differ among the types of vaccines offered in this country. Methods: A population-based study using linked administrative data on vaccine registry and adverse events following immunization in 2021 and 2022. The study included 10,169,378 individuals aged 18 or over who lived in Bahia and received the first dose of COVID-19 vaccines. We calculated AEFI prevalence and verified differences among vaccines by logistic regression to estimate crude and adjusted by sex and age group prevalence ratio (PR). Results: The prevalence of AEFI was 74.3 per 100,000 doses applied, with a higher rate of nonserious events, mainly following the ChAdOx1-S. More than two-thirds of these adverse effects occurred in women, and almost half were between 30 and 49 years old. The individuals who received ChAdOx1-S had a 125% higher prevalence than those who received CoronaVac. Those who received BNT162b2 and Ad26.COV2.S had a 71% and 58%, respectively, lower prevalence of AEFI than those who received CoronaVac. Conclusions: The use of vaccines against COVID-19 has proven to be positive and effective in combating SARS-CoV-2, significantly reducing morbidity and mortality from the disease. We cannot deny the presence of adverse events in the context of vaccination. However, the vaccines have proven to be safe and reliable. The results of this study offer relevant data that can contribute to the qualification of AEFI pharmacovigilance in Brazil and worldwide. Full article

Objective: To evaluate the humoral response to and impact of SARS-CoV-2 vaccination in patients with systemic lupus erythematosus in a multicenter cohort design. Methods: Data for this analysis were obtained from the Study of Safety, Effectiveness and Duration of Immunity after Vaccination against SARS-CoV-2 in Patients with Immune-Mediated Inflammatory Diseases (SAFER), a prospective, multicenter, phase IV, real-world study conducted across different regions of Brazil from June/2021 to March/2024. Patients aged >18 years with systemic lupus erythematosus (SLE) who received any one of the SARS-CoV-2 vaccines approved by the Brazilian health regulatory agency (CoronaVac [inactivated SARS-CoV-2 vaccine], ChAdOx-1 [AstraZeneca], or BNT162b2 [Pfizer-BioNTech]) were included. Immunogenicity was assessed in pre- and post-vaccination blood samples, and patients were monitored in person and remotely for the occurrence and severity of COVID-19. Results: Two hundred and thirty-five patients with SLE who had completed their vaccination schedules (two doses + booster dose) were included in this study. Most patients were female (89.3%) and had low disease activity or were in remission (72.4%); the majority were also on some form of immunosuppressive therapy (58.1%). One hundred and sixteen patients received two doses of CoronaVac followed by one dose of BNT162b2 (Pfizer-BioNTech) vaccine, eighty-seven received two doses of ChAdOx1-S (AstraZeneca) followed by one dose of BNT162b2 (Pfizer-BioNTech) vaccine, and thirty-two received three doses of BNT162b2 (Pfizer-BioNTech) vaccine. Twenty-eight cases of COVID-19, none meeting criteria for severe COVID-19, were recorded in patients with respiratory symptoms after the second dose of a SARS-CoV-2 vaccine. Regarding immunogenicity, an increase in seroconversion rate was observed following consecutive vaccine doses, with no difference between vaccination schedules, reaching 97.57% seropositivity after a booster dose. The geometric mean IgG titers differed between the different vaccination schedules after the first and the second vaccine dose, being lowest for the CoronaVac-based schedule, but titers were similar after the administration of a booster dose. Conclusion: In patients with SLE, SARS-CoV-2 vaccines are immunogenic, inducing a robust humoral response. No severe outcomes associated with death or hospitalization were found in the evaluated patient sample. Complete vaccination schedules including a booster dose induced higher humoral responses than incomplete schedules, especially in patients initially immunized with an inactivated virus vaccine schedule and those with a suboptimal humoral response. Full article

Background/Objectives: This study aimed to determine the percentage and duration of neutralizing antibodies against the Omicron variant in human milk after vaccination against SARS-CoV-2, considering the three different vaccine technologies approved in Brazil. Methods: A cross-sectional study was conducted with lactating women who received the complete vaccination cycle with available vaccines (AstraZeneca, Pfizer, CoronaVac, and Janssen). The participants resided in Rio de Janeiro, and samples were collected from April to October 2022. Breast milk was analyzed for evidence of neutralizing antibodies using specific assays for the Omicron variant. Results: The results showed that all types of vaccines were effective in inducing neutralizing antibodies in breast milk regardless of the vaccine technology used. There was no significant difference between women receiving two or three doses. Exclusive breastfeeding was significantly associated with higher percentages of neutralizing antibodies in breast milk compared to non-exclusive breastfeeding. Conclusions: These findings reinforce the importance of breastfeeding as a strategy to provide passive protection to infants, especially where vaccination for children under six months of age is not recommended. Full article

Background/Objectives: The effectiveness of COVID-19 vaccine in patients with immune-mediated inflammatory diseases (IMID) depends on the underlying disease, immunosuppression degree and the vaccine regimens. We evaluate the safety and immunogenicity of different COVID-19 vaccine schedules. Methods: The SAFER study: “Safety and effectiveness of the COVID-19 Vaccine in Rheumatic Disease”, is a Brazilian multicentric prospective observational phase IV study in the real-life. Data were analyzed after 2 or 3 doses of COVID-19 vaccines: adenoviral vectored vaccine (ChAdOx1 nCoV-19, Astrazeneca), mRNA vaccine (BNT162b2, Pfizer–BioNTech) or inactivated SARS-COV-2 vaccine (CoronaVac, Sinovac Biotech). IgG antibody against SARS-CoV-2 spike (IgG-S) receptor-binding domain level were quantified at baseline (T1) and 28 days after the first (T2), 2nd (T3) and 3rd (T4) doses by chemiluminescence (SARS-CoV-2-IgG-II Quant-assay, Abbott-Laboratories). Results: 721 patients with IMID were included in the analysis. The median titers of IgG-S (BAU/mL) increased progressively over the times: at baseline was 6.26 (5.41–7.24), T2: 73.01 (61.53–86.62), T3: 200.0 (174.36–229.41) and T4: 904.92 (800.49–1022.97). The multivariate linear regression showed that greater IgG-S titers were associated with pre-exposure to COVID-19 (p < 0.001) and BNT162b2 booster vaccine (p < 0.001). Rituximab and immunosuppressant drugs were independent factors for low titers (p = 0.002, p < 0.001, respectively). No serious adverse event was reported. Conclusions: All platforms were safe and induced an increase in IgG-S antibodies. COVID-19 pre-exposure and BNT162b2 booster regimens were predictors of higher humoral immune responses, which is relevant in immunosuppressed populations. Immunosuppressants (mainly rituximab) predicted the lowest antibodies. Full article

Background: The global COVID-19 pandemic has resulted in approximately 7 million deaths and a historic vaccination effort, with over 13.6 billion doses administered. Despite this, understanding of immune responses in vulnerable populations, such as transplant recipients (TR) and hemodialysis patients (HD), remains limited, especially outside the US and Europe. Methods: To address this gap, we analyzed blood samples and deidentified data from the Instituto Nacional de Coordinación de Trasplante (INCORT) in The Dominican Republic, measuring antibody levels to SARS-CoV-2 post-infection and vaccination with BNT162b2 (Pfizer-BioNTech) and Sinovac-CoronaVac (Sinovac) in TR, HD, and healthy controls (CO). Using a fluorescent multiplex assay (mPlex-CoV) and mixed-effects modeling, we assessed variations in anti-S, anti-RBD, and anti-N IgG antibodies. Results: The results indicate that the CO group experienced an early peak in anti-S and anti-RBD antibodies, followed by stabilization. In contrast, the TR and HD groups showed a slower, gradual increase in antibodies. Despite fluctuations in the HD group, both the TR and HD groups maintained high anti-S and anti-RBD IgG levels, indicating a back-boosting effect from vaccination. However, elevated anti-N IgG levels in the TR and HD groups suggest potential reinfections. Additionally, prior SARS-CoV-2 infection led to higher anti-S IgG levels, with BNT162b2 associated with higher anti-S IgG and CoronaVac associated with higher anti-N IgG levels. Conclusion: These findings highlight the variability in antibody responses and the need for targeted public health strategies to diverse immunological profiles. Full article

The COVID-19 pandemic, caused by SARS-CoV-2, prompted global efforts to develop vaccines to control the disease. Various vaccines, including mRNA (BNT162b2, mRNA-1273), adenoviral vector (ChAdOx1, Ad26.COV2.S), and inactivated virus platforms (BBIBP-CorV, CoronaVac), elicit high-titer, protective antibodies against the virus, but long-term antibody durability and effectiveness vary. The objective of this study is to elucidate the factors that influence vaccine effectiveness (VE) and the longevity of humoral immune responses to COVID-19 vaccines through a review of the relevant literature, including clinical and real-world studies. Here, we discuss the humoral immune response to different COVID-19 vaccines and identify factors influencing VE and antibody longevity. Despite initial robust immune responses, vaccine-induced immunity wanes over time, particularly with the emergence of variants, such as Delta and Omicron, that exhibit immune escape mechanisms. Additionally, the durability of the humoral immune responses elicited by different vaccine platforms, along with the identification of essential determinants of long-term protection—like pre-existing immunity, booster doses, hybrid immunity, and demographic factors—are critical for protecting against severe COVID-19. Booster vaccinations substantially restore neutralizing antibody levels, especially against immune-evasive variants, while individuals with hybrid immunity have a more durable and potent immune response. Importantly, comorbidities such as diabetes, cardiovascular disease, chronic kidney disease, and cancer significantly reduce the magnitude and longevity of vaccine-induced protection. Immunocompromised individuals, particularly those undergoing chemotherapy and those with hematologic malignancies, have diminished humoral responses and benefit disproportionately from booster vaccinations. Age and sex also influence immune responses, with older adults experiencing accelerated antibody decline and females generally exhibiting stronger humoral responses compared to males. Understanding the variables affecting immune protection is crucial to improving vaccine strategies and predicting VE and protection against COVID-19. Full article

Background: During the COVID-19 pandemic, three different types of inactivated SARS-CoV-2 vaccines, namely BBIBP-CorV, WIBP-CorV and CoronaVac, were manufactured and used for vaccination in China. However, as far as we know, no comparison of their induced serum neutralization has been carried out so far, possibly due to the regional difference in vaccine distribution, the difficulty in undertaking a comprehensive evaluation, and the intention to avoid unnecessary bias in populations for a certain type of inactivated vaccine.Methods: Since all three of these inactivated vaccines are no longer produced and used for vaccination, here, we retrospectively compared the serum neutralizing activities induced by these three different types of inactivated SARS-CoV-2 vaccines. Results: Compared with unvaccinated uninfected control donors, primary inactivated vaccination (232 donors) induced increased serum neutralizing titers against wildtype SARS-CoV-2 in around 70% of donors during the first 100 days. However, the neutralization effect waned quickly after 100 days, and significantly diminished against Delta and Omicron (B.1.1.529) variants. Moreover, the newly emerged Omicron variants, such as BA.2.75, BA.4/5, BF.7, BQ.1.1, and XBB, almost fully evaded the induced serum neutralization activity. Conclusions: These three distinct types of inactivated vaccines, namely BBIBP-CorV, WIBP-CorV, and CoronaVac, induced serum neutralization in most vaccinated populations but in a short-term and variant-evaded manner with no significant difference among these inactivated vaccines. Full article