COVID-19 mRNA Vaccination Generates Greater Immunoglobulin G Levels in Women Compared to Men

The impact of Bacillus Calmette-Guérin vaccination on antibody response after COVID-19 vaccination

Earlier studies showed that BCG vaccination improves antibody responses of subsequent vaccinations. Similarly, in older volunteers we found an increased IgG receptor-binding domain (RBD) concentration after SARS-CoV-2 infection if they were recently vaccinated with BCG. This study aims to assess the effect of BCG on the serum antibody concentrations induced by COVID-19 vaccination in a population of adults older than 60 years. Serum was collected from 1,555 participants of the BCG-CORONA-ELDERLY trial a year after BCG or placebo, and we analyzed the anti-SARS-CoV-2 antibody concentrations using a fluorescent-microsphere-based multiplex immunoassay. Individuals who received the full primary COVID-19 vaccination series before serum collection and did not test positive for SARS-CoV-2 between inclusion and serum collection were included in analyses (n = 945). We found that BCG vaccination before first COVID-19 vaccine (median 347 days [IQR 329-359]) did not significantly impact the IgG RBD concentration after COVID-19 vaccination in an older European population.

SARS-CoV-2 spike antigen-specific B cell and antibody responses in pre-vaccination period COVID-19 convalescent males and females with or without post-covid condition

Background

Following SARS-CoV-2 infection a significant proportion of convalescent individuals develop the post-COVID condition (PCC) that is characterized by wide spectrum of symptoms encompassing various organs. Even though the underlying pathophysiology of PCC is not known, detection of viral transcripts and antigens in tissues other than lungs raise the possibility that PCC may be a consequence of aberrant immune response to the viral antigens. To test this hypothesis, we evaluated B cell and antibody responses to the SARS-CoV-2 antigens in PCC patients who experienced mild COVID-19 disease during the pre-vaccination period of COVID-19 pandemic.

Methods

The study subjects included unvaccinated male and female subjects who developed PCC or not (No-PCC) after clearing RT-PCR confirmed mild COVID-19 infection. SARS-CoV-2 D614G and omicron RBD specific B cell subsets in peripheral circulation were assessed by flow cytometry. IgG, IgG3 and IgA antibody titers toward RBD, spike and nucleocapsid antigens in the plasma were evaluated by ELISA.

Results

The frequency of the B cells specific to D614G-RBD were comparable in convalescent groups with and without PCC in both males and females. Notably, in females with PCC, the anti-D614G RBD specific double negative (IgD-CD27-) B cells showed significant correlation with the number of symptoms at acute of infection. Anti-spike antibody responses were also higher at 3 months post-infection in females who developed PCC, but not in the male PCC group. On the other hand, the male PCC group also showed consistently high anti-RBD IgG responses compared to all other groups.

Conclusions

The antibody responses to the spike protein, but not the anti-RBD B cell responses diverge between convalescent males and females who develop PCC. Our findings also suggest that sex-related factors may also be involved in the development of PCC via modulating antibody responses to the SARS-CoV-2 antigens.

Comparison of Humoral Antibody Responses and Seroconversion Rates between Two Homologous ChAdOx1 nCoV-19 and mRNA-1273 Vaccination in Patients Undergoing Maintenance Hemodialysis

BACKGROUND

Hemodialysis patients are at an increased risk of SARS-CoV-2 infection and are excluded from preauthorization COVID-19 vaccine trials; therefore, their immunogenicity is uncertain.

METHODS

To compare the antibody responses to homologous ChAdOx1 and mRNA-1273 SARS-CoV-2 vaccination in hemodialysis patients, 103 age- and sex-matched hemodialysis patients with two homologous prime-boost vaccinations were recruited to detect anti-receptor-binding domain (RBD) IgG levels and seroconversion rates (SCRs) 14 days after a prime dose (PD14), before and 28 days after a boost dose (pre-BD0 and BD28).

RESULTS

Both mRNA-1273 and ChAdOx1 vaccinations elicited immunogenicity in study subjects, and the former induced higher anti-RBD IgG levels than the latter. The SCRs of both groups increased over time and varied widely from 1.82% to 97.92%, and were significantly different at PD14 and pre-BD0 regardless of different thresholds. At BD28, the SCRs of the ChAdOx1 group and the mRNA-1273 group were comparable using a threshold ≥ 7.1 BAU/mL (93.96% vs. 97.92%) and a threshold ≥ 17 BAU/mL (92.73% vs. 97.92%), respectively, but they were significantly different using a threshold ≥ 20.2% of convalescent serum anti-RBD levels (52.73% vs. 95.83%). The seroconversion (≥20.2% of convalescent level) at BD28 was associated with mRNA-1273 vaccination after being adjusted for age, sex, body mass index, and the presence of solicited reactogenicity after a prime vaccination.

CONCLUSION

Our prospective, observational cohort indicates that a full prime-boost mRNA-1273 vaccination is likely to provide higher immune protection in hemodialysis patients compared to ChAdOx1, and this population with a prime-boost ChAdOx1 vaccination should be prioritized for a third dose.

Predictors of long-term neutralizing antibody titers following COVID-19 vaccination by three vaccine types: the BOOST study

As concerns related to the COVID-19 pandemic continue, it is critical to understand the impact of vaccination type on neutralizing antibody response durability as well as to identify individual difference factors related to decline in neutralization. This was a head-to-head comparison study following 498 healthy, community volunteers who received the BNT162b2 (n = 287), mRNA-1273 (n = 149), and Ad26.COV2.S (n = 62). Participants completed questionnaires and underwent blood draws prior to vaccination, 1 month, and 6 months after the vaccination series, and neutralizing antibody (nAB) titers at 1- and 6-months post vaccination were quantified using a high-throughput pseudovirus assay. Over 6 months of follow-up, nABs declined in recipients of BNT162b2 and mRNA-1273, while nABs in recipients of Ad26.COV2.S showed a significant increase. At the 6-month time point, nABs to Ad26.COV2.S were significantly higher than nABs to BNT162b2 and equivalent to mRNA-1273. Irrespective of follow-up timing, being older was associated with lower nAB for participants who received BNT162b2 and Ad26.COV2.S but not for those who received mRNA-1273. A higher baseline BMI was associated with a lower nAB for Ad26.COV2.S recipients but not for recipients of other vaccines. Women and non-smokers showed higher nAB compared to men and current smokers, respectively. The durability of neutralizing antibody responses differed by vaccine type and several sociodemographic factors that predicted response. These findings may inform booster recommendations in the future.

A meta-analysis of the associations between insufficient sleep duration and antibody response to vaccination

Vaccination is a major strategy to control a viral pandemic. Simple behavioral interventions that might boost vaccine responses have yet to be identified. We conducted meta-analyses to summarize the evidence linking the amount of sleep obtained in the days surrounding vaccination to antibody response in healthy adults. Authors of the included studies provided the information needed to accurately estimate the pooled effect size (ES) and 95% confidence intervals (95% CI) and to examine sex differences.^{1,2,3,4,5,6,7} The association between self-reported short sleep (<6 h/night) and reduced vaccine response did not reach our pre-defined statistical significant criteria (total n = 504, ages 18-85; overall ES [95% CI] = 0.29 [-0.04, 0.63]). Objectively assessed short sleep was associated with a robust decrease in antibody response (total n = 304, ages 18-60; overall ES [95% CI] = 0.79 [0.40, 1.18]). In men, the pooled ES was large (overall ES [95% CI] = 0.93 [0.54, 1.33]), whereas it did not reach significance in women (overall ES [95% CI] = 0.42 [-0.49, 1.32]). These results provide evidence that insufficient sleep duration substantially decreases the response to anti-viral vaccination and suggests that achieving adequate amount of sleep during the days surrounding vaccination may enhance and prolong the humoral response. Large-scale well-controlled studies are urgently needed to define (1) the window of time around inoculation when optimizing sleep duration is most beneficial, (2) the causes of the sex disparity in the impact of sleep on the response, and (3) the amount of sleep needed to protect the response.

Endocrine Disorders and COVID-19

The multifaceted interaction between coronavirus disease 2019 (COVID-19) and the endocrine system has been a major area of scientific research over the past two years. While common endocrine/metabolic disorders such as obesity and diabetes have been recognized among significant risk factors for COVID-19 severity, several endocrine organs were identified to be targeted by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). New-onset endocrine disorders related to COVID-19 were reported while long-term effects, if any, are yet to be determined. Meanwhile, the "stay home" measures during the pandemic caused interruption in the care of patients with pre-existing endocrine disorders and may have impeded the diagnosis and treatment of new ones. This review aims to outline this complex interaction between COVID-19 and endocrine disorders by synthesizing the current scientific knowledge obtained from clinical and pathophysiological studies, and to emphasize considerations for future research.

The Levels of Anti-SARS-CoV-2 Spike Protein IgG Antibodies Before and After the Third Dose of Vaccination Against COVID-19

Purpose

The COVID-19 pandemic has been going on for almost three years, and so far, many preventive and therapeutic strategies have been developed. The issue of subsequent booster vaccinations is currently being discussed. We aimed to analyze how the third dose of vaccination against COVID-19 correlates with the dynamics of IgG anti-SARS-CoV-2 spike protein antibody levels in a group of healthy people.

Patients and Methods

The prospective study included 93 participants before and after a second booster of COVID-19 vaccination, from whom 4 blood samples were collected at intervals. The levels of IgG anti-SARS-CoV-2 in serum were identified using the chemiluminescent immunoassay specific for the receptor-binding domain (RBD) of the S1 protein. The analysis of the results was performed using appropriate statistical methods, considering p <0.05 as a statistically significant value.

Results

The IgG levels were significantly higher and less diverse after the same follow-up time from the second booster vaccination compared to the first booster. The antibody levels were positively correlated with female, healthcare workers, the elderly and participants with a negative COVID-19 history. Furthermore, the increase in IgG antibodies after the second booster vaccination correlated inversely with the baseline level of antibodies before the vaccination. The latest results showed that antibody levels dropped 1.5-fold after approx. 10 months from the second booster vaccination but still remained at a protective level.

Conclusion

Booster vaccinations seem to better stimulate immune memory, and in the case of borderline IgG level induces the greatest increase in antibodies. It is worth considering the individual parameters of patients and measuring antibodies before vaccination.

No difference in anti-spike antibody and surrogate viral neutralization following SARS-CoV-2 booster vaccination in persons with HIV compared to controls (CO-HIV Study)

Background

Understanding the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination will enable accurate counseling and inform evolving vaccination strategies. Little is known about antibody response following booster vaccination in people living with HIV (PLWH).

Methods

We enrolled SARS-CoV-2 vaccinated PLWH and controls without HIV in similar proportions based on age and comorbidities. Participants completed surveys on prior SARS-CoV-2 infection, vaccination, and comorbidities, and provided self-collected dried blood spots (DBS). Quantitative anti-spike IgG and surrogate viral neutralization assays targeted wild-type (WT), Delta, and Omicron variants. We also measured quantitative anti-nucleocapsid IgG. The analysis population had received full SARS-CoV-2 vaccination plus one booster dose. Bivariate analyses for continuous outcomes utilized Wilcoxon tests and multivariate analysis used linear models.

Results

The analysis population comprised 140 PLWH and 75 controls with median age 58 and 55 years, males 95% and 43%, and DBS collection on 112 and 109 days after the last booster dose, respectively. Median CD4 count among PLWH was 760 cells/mm3 and 91% had an undetectable HIV-1 viral load. Considering WT, Delta, and Omicron variants, there was no significant difference in mean quantitative anti-spike IgG between PLWH (3.3, 2.9, 1.8) and controls (3.3, 2.9, 1.8), respectively (p-values=0. 771, 0.920, 0.708). Surrogate viral neutralization responses were similar in PLWH (1.0, 0.9, and 0.4) and controls (1.0, 0.9, 0.5), respectively (p-values=0.594, 0.436, 0.706).

Conclusions

PLWH whose CD4 counts are well preserved and persons without HIV have similar anti-spike IgG antibody levels and viral neutralization responses after a single SARS-CoV-2 booster vaccination.

Effects of Biological Sex and Pregnancy on SARS-CoV-2 Pathogenesis and Vaccine Outcomes

SARS-CoV-2 is the causative agent of COVID-19 in humans and has resulted in the death of millions of people worldwide. Similar numbers of infections have been documented in males and females; males, however, are more likely than females to be hospitalized, require intensive care unit, or die from COVID-19. The mechanisms that account for this are multi-factorial and are likely to include differential expression of ACE2 and TMPRSS2 molecules that are required for viral entry into hosts cells and sex differences in the immune response, which are due to modulation of cellular functions by sex hormones and differences in chromosomal gene expression. Furthermore, as comorbidities are also associated with poorer outcomes to SARS-CoV-2 infection and several comorbidities are overrepresented in males, these are also likely to contribute to the observed sex differences. Despite their relative better prognosis following infection with SARS-CoV-2, females do have poorer outcomes during pregnancy. This is likely to be due to pregnancy-induced changes in the immune system that adversely affect viral immunity and disruption of the renin-angiotensin system. Importantly, vaccination reduces the severity of disease in males and females, including pregnant females, and there is no evidence that vaccination has any adverse effects on the outcomes of pregnancy.

Antibody responses to COVID-19 vaccination in people with obesity: A systematic review and meta-analysis

COVID-19 vaccine is critical in preventing SARS-CoV-2 infection and transmission. However, obesity's effect on immune responses to COVID-19 vaccines is still unknown. We performed a meta-analysis of the literature and compared antibody responses with COVID-19 vaccines among persons with and without obesity. We used Pubmed, Embase, Web of Science, and Cochrane Library to identify all related studies up to April 2022. The Stata.14 software was used to analyze the selected data. Eleven studies were included in the present meta-analysis. Five of them provided absolute values of antibody titers in the obese group and non-obese group. Overall, we found that the obese population was significantly associated with lower antibody titers (standardized mean difference [SMD] = -0.228, 95% CI [-0.437, -0.019], P < 0.001) after COVID-19 vaccination. Significant heterogeneity was present in most pooled analyses but was reduced after subgroup analyses. No publication bias was observed in the present analysis. The Trim and Fill method did not change the results in the primary analysis. The present meta-analysis suggested that obesity was significantly associated with decreased antibody responses to SARS-CoV-2 vaccines. Future studies should be performed to unravel the mechanism of response to the COVID-19 vaccine in obese individuals.

Vaccine-induced seroconversion in participants in the North Carolina COVID-19 community Research Partnership

Well-regulated clinical trials have shown FDA-approved COVID-19 vaccines to be immunogenic and highly efficacious. We evaluated seroconversion rates in adults reporting ≥ 1 dose of an mRNA COVID-19 vaccine in a cohort study of nearly 8000 adults residing in North Carolina to validate immunogenicity using a novel approach: at-home, participant administered point-of-care testing. Overall, 91.4% had documented seroconversion within 75 days of first vaccination (median: 31 days). Participants who were older and male participants were less likely to seroconvert (adults aged 41-65: adjusted hazard ratio [aHR] 0.69 [95% confidence interval (CI): 0.64, 0.73], adults aged 66-95: aHR 0.55 [95% CI: 0.50, 0.60], compared to those 18-40; males: aHR 0.92 [95% CI: 0.87, 0.98], compared to females). Participants with evidence of prior infection were more likely to seroconvert than those without (aHR 1.50 [95% CI: 1.19, 1.88]) and those receiving BNT162b2 were less likely to seroconvert compared to those receiving mRNA-1273 (aHR 0.84 [95% CI: 0.79, 0.90]). Reporting at least one new symptom after first vaccination did not affect time to seroconversion, but participants reporting at least one new symptom after second vaccination were more likely to seroconvert (aHR 1.11 [95% CI: 1.05, 1.17]). This data demonstrates the high community-level immunogenicity of COVID-19 vaccines, albeit with notable differences in older adults, and feasibility of using at-home, participant administered point-of-care testing for community cohort monitoring. Trial registration: ClinicalTrials.gov NCT04342884.

Spike-antibody responses to COVID-19 vaccination by demographic and clinical factors in a prospective community cohort study

Vaccination constitutes the best long-term solution against Coronavirus Disease-2019; however, vaccine-derived immunity may not protect all groups equally, and the durability of protective antibodies may be short. We evaluate Spike-antibody responses following BNT162b2 or ChAdOx1-S vaccination amongst SARS-CoV2-naive adults across England and Wales enrolled in a prospective cohort study (Virus Watch). Here we show BNT162b2 recipients achieved higher peak antibody levels after two doses; however, both groups experience substantial antibody waning over time. In 8356 individuals submitting a sample ≥28 days after Dose 2, we observe significantly reduced Spike-antibody levels following two doses amongst individuals reporting conditions and therapies that cause immunosuppression. After adjusting for these, several common chronic conditions also appear to attenuate the antibody response. These findings suggest the need to continue prioritising vulnerable groups, who have been vaccinated earliest and have the most attenuated antibody responses, for future boosters.

Systemic and mucosal IgA responses are variably induced in response to SARS-CoV-2 mRNA vaccination and are associated with protection against subsequent infection

Although SARS-CoV-2 infects the upper respiratory tract, we know little about the amount, type, and kinetics of antibodies (Ab) generated in the oral cavity in response to COVID-19 vaccination. We collected serum and saliva samples from participants receiving two doses of mRNA COVID-19 vaccines and measured the level of anti-SARS-CoV-2 Ab. We detected anti-Spike and anti-Receptor Binding Domain (RBD) IgG and IgA, as well as anti-Spike/RBD associated secretory component in the saliva of most participants after dose 1. Administration of a second dose of mRNA boosted the IgG but not the IgA response, with only 30% of participants remaining positive for IgA at this timepoint. At 6 months post-dose 2, these participants exhibited diminished anti-Spike/RBD IgG levels, although secretory component-associated anti-Spike Ab were more stable. Examining two prospective cohorts we found that participants who experienced breakthrough infections with SARS-CoV-2 variants had lower levels of vaccine-induced serum anti-Spike/RBD IgA at 2-4 weeks post-dose 2 compared to participants who did not experience an infection, whereas IgG levels were comparable between groups. These data suggest that COVID-19 vaccines that elicit a durable IgA response may have utility in preventing infection. Our study finds that a local secretory component-associated IgA response is induced by COVID-19 mRNA vaccination that persists in some, but not all participants. The serum and saliva IgA response modestly correlate at 2-4 weeks post-dose 2. Of note, levels of anti-Spike serum IgA (but not IgG) at this timepoint are lower in participants who subsequently become infected with SARS-CoV-2. As new surges of SARS-CoV-2 variants arise, developing COVID-19 booster shots that provoke high levels of IgA has the potential to reduce person-to-person transmission.

Characterization of Clinical Features of Hospitalized Patients Due to the SARS-CoV-2 Infection in the Absence of Comorbidities Regarding the Sex: An Epidemiological Study of the First Year of the Pandemic in Brazil

The male sex, due to the presence of genetic, immunological, hormonal, social, and environmental factors, is associated with higher severity and death in Coronavirus Disease (COVID)-19. We conducted an epidemiological study to characterize the COVID-19 clinical profile, severity, and outcome according to sex in patients with the severe acute respiratory syndrome (SARS) due to the fact of this disease. We carried out an epidemiological analysis using epidemiological data made available by the OpenDataSUS, which stores information about SARS in Brazil. We recorded the features of the patients admitted to the hospital for SARS treatment due to the presence of COVID-19 (in the absence of comorbidities) and associated these characteristics with sex and risk of death. The study comprised 336,463 patients, 213,151 of whom were men. Male patients presented a higher number of clinical signs, for example, fever (OR = 1.424; 95%CI = 1.399−1.448), peripheral arterial oxygen saturation (SpO2) < 95% (OR = 1.253; 95%CI = 1.232−1.274), and dyspnea (OR = 1.146; 95%CI = 1.125−1.166) as well as greater need for admission in intensive care unit (ICU, OR = 1.189; 95%CI = 1.168−1.210), and the use of invasive ventilatory support (OR = 1.306; 95%CI = 1.273−1.339) and noninvasive ventilatory support (OR = 1.238; 95%CI = 1.216−1.260) when compared with female patients. Curiously, the male sex was associated only with a small increase in the risk of death when compared with the female sex (OR = 1.041; 95%CI = 1.023−1.060). We did a secondary analysis to identify the main predictors of death. In that sense, the multivariate analysis enabled the prediction of the risk of death, and the male sex was one of the predictors (OR = 1.101; 95%CI = 1.011−1.199); however, with a small effect size. In addition, other factors also contributed to this prediction and presented a great effect size, they are listed below: older age (61−72 years old (OR = 15.778; 95%CI = 1.865−133.492), 73−85 years old (OR = 31.978; 95%CI = 3.779−270.600), and +85 years old (OR = 68.385; 95%CI = 8.164−589.705)); race (Black (OR = 1.247; 95%CI = 1.016−1.531), Pardos (multiracial background; OR = 1.585; 95%CI = 1.450−1.732), and Indigenous (OR = 3.186; 95%CI = 1.927−5.266)); clinical signs (for instance, dyspnea (OR = 1.231; 95%CI = 1.110−1.365) and SpO2 < 95% (OR = 1.367; 95%CI = 1.238−1.508)); need for admission in the ICU (OR = 3.069; 95%CI = 2.789−3.377); and for ventilatory support (invasive (OR = 10.174; 95%CI = 8.803−11.759) and noninvasive (OR = 1.609; 95%CI = 1.438−1.800)). In conclusion, in Brazil, male patients tend to present the phenotype of higher severity in COVID-19, however, with a small effect on the risk of death.

COVID-19 booster vaccination during pregnancy enhances maternal binding and neutralizing antibody responses and transplacental antibody transfer to the newborn (DMID 21-0004)

IMPORTANCE

COVID-19 vaccination is recommended during pregnancy for the protection of the mother. Little is known about the immune response to booster vaccinations during pregnancy.

OBJECTIVE

To measure immune responses to COVID-19 primary and booster mRNA vaccination during pregnancy and transplacental antibody transfer to the newborn.

DESIGN

Prospective cohort study of pregnant participants enrolled from July 2021 to January 2022, with follow up through and up to 12 months after delivery.

SETTING

Multicenter study conducted at 9 academic sites.

PARTICIPANTS

Pregnant participants who received COVID-19 vaccination during pregnancy and their newborns.

EXPOSURES

Primary or booster COVID-19 mRNA vaccination during pregnancy.

MAIN OUTCOMES AND MEASURES

SARS-CoV-2 binding and neutralizing antibody (nAb) titers after primary or booster COVID-19 mRNA vaccination during pregnancy and antibody transfer to the newborn. Immune responses were compared between primary and booster vaccine recipients in maternal sera at delivery and in cord blood, after adjusting for days since last vaccination.

RESULTS

In this interim analysis, 167 participants received a primary 2-dose series and 73 received a booster dose of mRNA vaccine during pregnancy. Booster vaccination resulted in significantly higher binding and nAb titers, including to the Omicron BA.1 variant, in maternal serum at delivery and cord blood compared to a primary 2-dose series (range 0.55 to 0.88 log ₁₀ higher, p<0.0001 for all comparisons). Although levels were significantly lower than to the prototypical D614G variant, nAb to Omicron were present at delivery in 9% (GMT ID50 12.7) of Pfizer and 22% (GMT ID50 14.7) of Moderna recipients, and in 73% (GMT ID50 60.2) of boosted participants (p<0.0001). Transplacental antibody transfer was efficient regardless of vaccination regimen (median transfer ratio range: 1.55-1.77 for binding IgG and 1.00-1.78 for nAb).

CONCLUSIONS AND RELEVANCE

COVID-19 mRNA vaccination during pregnancy elicited robust immune responses in mothers and efficient transplacental antibody transfer to the newborn. A booster dose during pregnancy significantly increased maternal and cord blood antibody levels, including against Omicron.Findings support continued use of COVID-19 vaccines during pregnancy, including booster doses.

TRIAL REGISTRATION

clinical trials.gov; Registration Number: NCT05031468 ; https://clinicaltrials.gov/ct2/show/NCT05031468.

KEY POINTS

Question: What is the immune response after COVID-19 booster vaccination during pregnancy and how does receipt of a booster dose impact transplacental antibody transfer to the newborn?Findings: Receipt of COVID-19 mRNA vaccines during pregnancy elicited robust binding and neutralizing antibody responses in the mother and in the newborn. Booster vaccination during pregnancy elicited significantly higher antibody levels in mothers at delivery and cord blood than 2-dose vaccination, including against the Omicron BA.1 variant.Meaning: COVID-19 vaccines, especially booster doses, should continue to be strongly recommended during pregnancy.

Humoral response to SARS-CoV-2 vaccines in people living with HIV

PURPOSE

To describe the humoral immune response to COVID-19 vaccines in people living with HIV and identify factors associated with the magnitude of anti-SARS-CoV-2 antibody concentrations.

METHODS

Retrospective analysis of electronic patient files in a big single HIV center in Munich, Germany. Non-parametric methods were used for descriptive and comparative statistics. Generalized linear models were used to analyze associations of general and HIV-specific variables with anti-SARS-CoV-2 antibody concentrations after standard vaccination.

RESULT

Overall, 665 people living with HIV were included into the analysis (median age: 53 [IQR: 43; 59]), 560 [84.2%] males). Median concentration of anti-SARS-CoV-2-antibodies was 1400 (IQR 664; 2130) BAU/mL. In 18 (2.7%) subjects, antibody concentrations below the threshold of 34 BAU/mL were found. Among PLWH with CD4 cell count < 200 cells/µL, median anti-SARS-CoV-2-Abs were 197 (IQR 44.6; 537.2) as compared to 1420 (IQR 687; 2216) for the group ≥ 200 cells/µL (p < 0.001). In a cumulative logit model, a vaccination scheme including an mRNA vaccine [OR: 4.64 (3.58; 6.02)], being female [OR: 2.14 (1.76; 2.61)], and having higher CD4 cells [OR per 100 cells/µL: 1.06 (1.04; 1.08)] were significantly associated with anti-SARS-CoV-2 antibody concentrations in higher quartiles, when adjusted for the time after vaccination.

CONCLUSION

We found a robust antibody response in people living with HIV undergoing standard vaccination against SARS-CoV-2. mRNA-containing vaccination schemes, being female, and having a higher CD4 cell count was associated with a higher concentration of antibodies in people living with HIV in our study sample. Particularly in the subgroup with CD4 cell counts < 200 cells/µL, antibody response was poor.

Demographic and clinical characteristics associated with variations in antibody response to BNT162b2 COVID-19 vaccination among healthcare workers at an academic medical centre: a longitudinal cohort analysis

OBJECTIVES

We sought to understand the demographic and clinical factors associated with variations in longitudinal antibody response following completion of two-dose regiment of BNT162b2 vaccination.

DESIGN

This study is a 10-month longitudinal cohort study of healthcare workers and serially measured anti-spike protein IgG (IgG-S) antibody levels using mixed linear models to examine their associations with participant characteristics.

SETTING

A large, multisite academic medical centre in Southern California, USA.

PARTICIPANTS

A total of 843 healthcare workers met inclusion criteria including completion of an initial two-dose course of BNT162b2 vaccination, complete clinical history and at least two blood samples for analysis. Patients had an average age of 45±13 years, were 70% female and 7% with prior SARS-CoV-2 infection.

RESULTS

Vaccine-induced IgG-S levels remained in the positive range for 99.6% of individuals up to 10 months after initial two-dose vaccination. Prior SARS-CoV-2 infection was the primary correlate of sustained higher postvaccination IgG-S levels (partial R2=0.133), with a 1.74±0.11 SD higher IgG-S response (p<0.001). Female sex (beta 0.27±0.06, p<0.001), younger age (0.01±0.00, p<0.001) and absence of hypertension (0.17±0.08, p=0.003) were also associated with persistently higher IgG-S responses. Notably, prior SARS-CoV-2 infection augmented the associations of sex (-0.42 for male sex, p=0.08) and modified the associations of hypertension (1.17, p=0.001), such that infection-naïve individuals with hypertension had persistently lower IgG-S levels whereas prior infected individuals with hypertension exhibited higher IgG-S levels that remained augmented over time.

CONCLUSIONS

While the IgG-S antibody response remains in the positive range for up to 10 months following initial mRNA vaccination in most adults, determinants of sustained higher antibody levels include prior SARS-CoV-2 infection, female sex, younger age and absence of hypertension. Certain determinants of the longitudinal antibody response appear significantly modified by prior infection status. These findings offer insights regarding factors that may influence the 'hybrid' immunity conferred by natural infection combined with vaccination.

Heterologous ChAdOx1 and BNT162b2 vaccination induces strong neutralizing antibody responses against SARS-CoV-2 including delta variant with tolerable reactogenicity

OBJECTIVES

We assessed humoral responses and reactogenicity following the heterologous vaccination compared to the homologous vaccination groups.

METHODS

We enrolled healthcare workers (HCWs) who were either vaccinated with ChAdOx1 followed by BNT162b2 (heterologous group) or two doses of ChAdOx1 (ChAdOx1 group) or BNT162b2 (BNT162b2 group). Immunogenicity was assessed by measuring antibody titers against receptor-binding domain (RBD) of SARS-CoV-2 spike protein in all participants and neutralizing antibody titer in 100 participants per group. Reactogenicity was evaluated by a questionnaire-based survey.

RESULTS

We enrolled 499 HCWs (ChAdOx1, n=199; BNT162b2, n=200; heterologous ChAdOx1/BNT162b2, n=100). The geometric mean titer of anti-RBD antibody at 14 days after the booster dose was significantly higher in the heterologous group (11780.55 BAU/mL [95% CI, 10891.52-12742.14]) than in the ChAdOx1 (1561.51 [1415.03-1723.15]) or BNT162b2 (2895.90 [2664.01-3147.98]) groups (both P value<.001). The neutralizing antibody titer of the heterologous group (geometric mean ND_50, 2367.74 [1970.03-2845.74]) was comparable to that of the BNT162b2 group (2118.63 [1755.88-2556.32], P >.05) but higher than that of the ChAdOx1 group (391.77 [326.16-470.59], P value<.001). Compared with those against wild-type SARS-CoV-2, the geometric mean neutralizing antibody titers against the delta variant at 14 days after the boosting were reduced by 3.0-fold in the heterologous group (geometric mean ND_50. 872.01 [95% CI, 685.33-1109.54]), 4.0-fold in the BNT162b2 group (337.93 [262.78-434.57]), and 3.2-fold in the ChAdOx1 group (206.61 [144.05-296.34]). The local or systemic reactogenicity after the booster dose in the heterologous group was higher than that of the ChAdOx1 group but comparable to that of the BNT162b2 group.

CONCLUSIONS

Heterologous ChAdOx1 followed by BNT162b2 vaccination with a 12-week interval induced a robust humoral immune response against SARS-CoV-2 including the delta variant that was comparable to the homologous BNT162b2 vaccination and stronger than the homologous ChAdOx1 vaccination, with a tolerable reactogenicity profile.

Antibody response of smokers to the COVID-19 vaccination: Evaluation based on cigarette dependence

Smokers may have lower antibody titers after vaccination with a coronavirus disease 2019 (COVID-19) mRNA vaccine. However, to the best of our knowledge, no study has evaluated antibody titers after COVID-19 vaccination based on the level of smokers' cigarette dependence. In this study, we measured the level of serum anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) spike protein receptor-binding domain (S-RBD) immunoglobulin-G (IgG) by enzyme linked immunosorbent assay of 55 actively smoking Japanese social workers (firefighters, paramedics, and rescue workers) who had received two doses of the BNT162b2 vaccine. Further, we assessed their cigarette dependence using the Fagerstrom Test for Nicotine Dependence (FTND), measured their serum cotinine levels, and tested for their correlation with anti-RBD IgG levels. Serum anti-SARS-CoV-2 S-RBD protein IgG levels after BNT162b2 vaccination showed a significant negative correlation with FTND (ρ = -0.426, p = 0.001). In addition, serum cotinine level showed a significant positive correlation with FTND (ρ = 0.470, p = 0.000). However, no significant negative correlation was noted between serum cotinine and serum anti-SARS-CoV-2 S-RBD protein IgG levels (ρ = -0.156, p = 0.256). Our results suggest that smokers with strong cigarette dependence have inadequate anti-SARS-CoV-2 S-RBD protein IgG levels after COVID-19 mRNA vaccination.

SARS-CoV-2 Antibody and T Cell Response after a Third Vaccine Dose in Hemodialysis Patients Compared with Healthy Controls

Hemodialysis (HD) patients have an increased risk of severe SARS-CoV-2 infection. In this study, we assess the impact of a third vaccine dose (3D) on antibody levels and T cell response in HD patients and a healthy control group in a prospective cohort study consisting of 60 HD patients and 65 healthy controls. Each participant received two doses of the BNT-162b2 mRNA vaccine and an mRNA vaccine 3D. The SARS-CoV-2 antibody response was measured 6 months after the second vaccine dose and 6 to 8 weeks after the 3D. We assessed INF-γ secretion 6–8 weeks post 3D in 24 healthy controls, 17 HD patients with a normal response, and 20 low responder HD patients. The groups were compared using univariate quantile regressions and multiple analyses. After the 3D, the SARS-CoV-2-specific antibody and INF-γ titers of most HD patients were comparable to those of healthy controls. A subgroup of HD patients who had shown a diminished antibody response after the first two vaccine doses developed a significantly lower antibody and INF-γ response compared to responder HD patients and controls even after the 3D. A new strategy is needed to protect low/non-responder HD patients from severe SARS-CoV-2 infection.

Humoral Immunogenicity and Reactogenicity of the Standard ChAdOx1 nCoV-19 Vaccination in Taiwan

Background: The ChAdOx1 nCoV-19 vaccine has been widely administered against SARS-CoV-2 infection; however, data regarding its immunogenicity, reactogenicity, and potential differences in responses among Asian populations remain scarce. Methods: 270 participants without prior COVID-19 were enrolled to receive ChAdOx1 nCoV-19 vaccination with a prime–boost interval of 8–9 weeks. Their specific SARS-CoV-2 antibodies, neutralizing antibody titers (NT50), platelet counts, and D-dimer levels were analyzed before and after vaccination. Results: The seroconversion rates of anti-RBD and anti-spike IgG at day 28 after a boost vaccination (BD28) were 100% and 95.19%, respectively. Anti-RBD and anti-spike IgG levels were highly correlated (r = 0.7891), which were 172.9 ± 170.4 and 179.3 ± 76.88 BAU/mL at BD28, respectively. The geometric mean concentrations (GMCs) of NT50 for all participants increased to 132.9 IU/mL (95% CI 120.0–147.1) at BD28 and were highly correlated with anti-RBD and anti-spike IgG levels (r = 0.8248 and 0.7474, respectively). Body weight index was statistically significantly associated with anti-RBD IgG levels (p = 0.035), while female recipients had higher anti-spike IgG levels (p = 0.038). The GMCs of NT50 declined with age (p = 0.0163) and were significantly different across age groups (159.7 IU/mL for 20–29 years, 99.4 IU/mL for ≥50 years, p = 0.0026). Injection-site pain, fever, and fatigue were the major reactogenicity, which were more pronounced after prime vaccination and in younger participants (<50 years). Platelet counts decreased and D-dimer levels increased after vaccination but were not clinically relevant. No serious adverse events or deaths were observed. Conclusion: The vaccine is well-tolerated and elicited robust humoral immunity against SARS-CoV-2 after standard prime–boost vaccination in Taiwanese recipients.

Delayed-interval BNT162b2 mRNA COVID-19 vaccination enhances humoral immunity and induces robust T cell responses

Delayed dosing intervals are a strategy to immunize a greater proportion of the population. In an observational study, we compared humoral and cellular responses in health care workers receiving two doses of BNT162b2 (Pfizer-BioNTech) vaccine at standard (3- to 6-week) and delayed (8- to 16-week) intervals. In the delayed-interval group, anti-receptor-binding domain antibody titers were significantly enhanced compared to the standard-interval group. The 50% plaque reduction neutralization test (PRNT50) and PRNT90 titers against wild-type (ancestral) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Alpha, Beta and Delta variants were higher in the delayed-interval group. Spike-specific polyfunctional CD4⁺ and CD8⁺ T cells expressing interferon-γ and interleukin-2 were comparable between the two groups. Here, we show that the strategy of delaying second doses of mRNA vaccination may lead to enhanced humoral immune responses, including improved virus neutralization against wild-type and variant SARS-CoV-2 viruses. This finding has potentially important implications as vaccine implementation continues across a greater proportion of the global population.

Dynamics of antibody response to CoronaVac vaccine

CoronaVac was the first vaccine approved in Brazil for use in healthcare workers (HCWs). However, there is limited information about it, with little long‐term evidence on post‐vaccination antibody persistence. This study evaluated the antibody response to SARS‐CoV‐2 in 1237 HCWs after the first (1D), second dose (2D), and 6 months postvaccination (6mA2D) with CoronaVac. The seropositivity was 88% at 1D, increasing to 99.8% at 2D, but decreasing to 97.9% at 6mA2D, which was also observed at the analyzed antibody levels. Interestingly, the levels in females were higher than males, and we found a positive correlation with previous SARS‐CoV‐2 infection. Participants with comorbidities had lower levels suggesting the need to monitor for a potential booster dose. Our findings suggest that CoronaVac induced a robust antibody response that wanes significantly over time. Further longitudinal studies are needed to identify whether the antibodies will decline or plateau at a lower level.

Our findings suggest that CoronaVac induced a robust antibody response that wanes significantly over time.

In our study, two doses of CoronaVac were capable of induction an antibody response in people ≥51 years old.

The seropositivity and the levels of antibodies were higher in females when compared to males.

We found a positive correlation with previous SARS‐CoV‐2 infection, previously infected participants had a significantly higher antibody response than previously uninfected participants.

Our findings suggest that patients with chronic diseases may need a booster shot of CoronaVac vaccine.

Individuals with immune‐mediated diseases developed a significant humoral response following the administration of two doses of CoronaVac, albeit with lower antibody titers.

The gut microbiome as a biomarker of differential susceptibility to SARS-CoV-2

Coronavirus disease 2019 (COVID-19) continues to exact a devastating global toll. Ascertaining the factors underlying differential susceptibility and prognosis following viral exposure is critical to improving public health responses. We propose that gut microbes may contribute to variation in COVID-19 outcomes. We synthesise evidence for gut microbial contributions to immunity and inflammation, and associations with demographic factors affecting disease severity. We suggest mechanisms potentially underlying microbially mediated differential susceptibility to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These include gut microbiome-mediated priming of host inflammatory responses and regulation of endocrine signalling, with consequences for the cellular features exploited by SARS-CoV-2 virions. We argue that considering gut microbiome-mediated mechanisms may offer a lens for appreciating differential susceptibility to SARS-CoV-2, potentially contributing to clinical and epidemiological approaches to understanding and managing COVID-19.

Serology study after BTN162b2 vaccination in participants previously infected with SARS-CoV-2 in two different waves versus naïve

Background

The antibody response to SARS-CoV-2 mRNA vaccines in individuals with waning immunity generated by a previous SARS-CoV-2 infection, as well as the patterns of IgA and IgM responses in previously infected and in naïve individuals are still poorly understood.

Methods

We performed a serology study in a cohort of BTN162b2 mRNA vaccine recipients who were immunologically naïve (N, n = 50) or had been previously infected with SARS-CoV-2 (P.I., n = 51) during the first (n = 25) or second (n = 26) pandemic waves in Italy, respectively. We measured IgG, IgM and IgA antibodies against the SARS-CoV-2 Spike (S) and IgG against the nucleocapsid (N) proteins, as well as the neutralizing activity of sera collected before vaccination, after the first and second dose of vaccine.

Results

Most P.I. individuals from the first pandemic wave who showed declining antibody titres responded to the first vaccine dose with IgG-S and pseudovirus neutralization titres that were significantly higher than those observed in N individuals after the second vaccine dose. In all recipients, a single dose of vaccine was sufficient to induce a potent IgA response that was not associated with serum neutralization titres. We observed an unconventional pattern of IgM responses that were elicited in only half of immunologically naïve subjects even after the second vaccine dose.

Conclusions

The response to a single dose of vaccine in P.I. individuals is more potent than that observed in N individuals after two doses. Vaccine-induced IgA are not associated with serum neutralization.

Sex Differences in Immunity to Viral Infections

The ongoing COVID-19 pandemic has increased awareness about sex-specific differences in immunity and outcomes following SARS-CoV-2 infection. Strong evidence of a male bias in COVID-19 disease severity is hypothesized to be mediated by sex differential immune responses against SARS-CoV-2. This hypothesis is based on data from other viral infections, including influenza viruses, HIV, hepatitis viruses, and others that have demonstrated sex-specific immunity to viral infections. Although males are more susceptible to most viral infections, females possess immunological features that render them more vulnerable to distinct immune-related disease outcomes. Both sex chromosome complement and related genes as well as sex steroids play important roles in mediating the development of sex differences in immunity to viral infections.