3rd Vaccination Research Articles

COVID-19 vaccination in patients with classic and variant hairy cell leukemia

AbstractPatients with the B-cell malignancy hairy cell leukemia (HCL) and the poorer-prognosis variant HCLv often receive anti-CD20 monoclonal antibodies (mAbs), which kill normal B cells, impairing humoral immunity. We measured COVID-19 antibodies after doses of COVID-19 vaccine in patients with HCL (n = 415) and HCLv (n = 32). After the second COVID-19 vaccine dose, spike antibody level most strongly correlated with normal B-cell levels (r = 0.365, P < .0001), followed by CD4+ T-cell count (r = 0.244, P = .0002), and was less related to immunoglobulin G level (r = 0.101, P = .14). Spike antibody also correlated with normal B cells after the third to fifth vaccine doses and with CD4+ count after the third dose. Normal B-cells were undetectable in 87% of patients within 6 months after the last dose of anti-CD20 mAb and were lower than in patients at 6 to 12 months (P = .0003), which, in turn, were lower than at 12 to 18 months (P = .0002). Infection with COVID-19 became more common after use of the third vaccine dose; spike antibody levels were higher in patients with prior infection (positive vs negative nucleocapsid antibodies; P < .0001). Spike antibodies decreased faster after ibrutinib or anti-CD20 mAb. We conclude that decreased levels of normal B cells in patients with HCL/HCLv, due to disease and/or anti-CD20 therapy, are associated with lower COVID-19 vaccination efficiency and such patients may not respond well to vaccines. The associated studies were registered at www.ClinicalTrials.gov as #NCT01087333 (HCL/HCLv) and #NCT04362865 (COVID-19).

Characteristics of neutralizing antibody titers of the SARS-CoV-2 vaccine in maintenance hemodialysis patients.

Hemodialysis patients have high COVID-19 severity and mortality rates. For this high-risk group of hemodialysis patients with SARS-CoV-2 infection, early SARS-CoV-2 vaccination is recommended to prevent infection and severe disease. Thus far, few reports have evaluated COVID-19 antibody titers in hemodialysis patients. In this study, we investigated the time course of antibody titers acquired by vaccination in patients on dialysis. The anti-SARS-CoV-2 spike protein S1 IgG (anti-SP-IgG) antibody titers were compared between 33 outpatient maintenance hemodialysis patients and 32 age- and sex-matched healthy subjects. Antibody tests were performed at five time points: 6 months after the 2nd vaccination, immediately before the 3rd vaccination (8 months after the 2nd vaccination), and 2 weeks, 1 month, and 3 months after the 3rd vaccination. The dialysis patient group had significantly lower values of anti-SP-IgG antibody titers than the control group 6 months after the 2nd vaccination (433.7 ± 36.24 vs. 650.2 (427.2 - 759.4) (AU/mL), p = 0.006) and immediately before the 3rd vaccination (219.3 (129.4 - 423.4) vs. 443.3 (267.1 - 600.4) (AU/mL), p = 0.034), but no significant differences were observed after the 3rd vaccination (19,000.0 (11,000.0 - 3,6000.0) vs. 23,500.0 (20,250.0 - 29,000.0) (AU/mL), p = 0.538). This study confirmed that patients undergoing hemodialysis were proven to have acquired sufficient antibody titers after the vaccination.

18-month longitudinal SARS COV-2 neutralizing antibody dynamics in haemodialysis patients receiving heterologous 3-dose vaccination (AZD-1222- AZD-1222- BNT162b2) in a lower middle income setting

BackgroundPatients with chronic kidney disease on haemodialysis (HD) were given priority COVID-19 vaccination due to increased disease risk. The immune response to COVID-19 vaccination in patients on HD was diminished compared to healthy individuals in 2-dose studies. This study aimed to evaluate seroconversion rate, neutralizing antibody (nAB) levels and longitudinal antibody dynamics to 3-dose heterologous vaccination against COVID-19 in a cohort of HD patients compared to healthy controls and assess patient factors associated with antibody levels.MethodsThis study was a case–control longitudinal evaluation of nAB dynamics in 74 HD patients compared to 37 healthy controls in a low/middle income setting. Corresponding samples were obtained from the two cohorts at time-points (TP) 1–1-month post 2nd dose of AZD1222 vaccine, TP2- 4 months post 2nd dose, TP4- 2 weeks post 3rd dose with BNT162b2 vaccine, TP5-5 months post 3rd dose and TP6-12 months post 3rd dose. Additional data is available at TP0- pre 2nd dose and TP3- 6 months post 2nd dose in HC and HD cohorts respectively. Anti-SARS-CoV-2 nAB were detected using Genscript cPassTM pseudoviral neutralization kit. Demographic and clinical details were obtained using an interviewer administered questionnaire.ResultsCohorts were gender matched while mean age of the HD cohort was 54.1yrs (vs HCs mean age, 42.6yrs, p < 0.05). Percentage seroconverted and mean/median antibody level (MAB) in the HD cohort vs HCs at each sampling point were, TP1-83.7% vs 100% (p < 0.05), MAB-450 IU/ml vs 1940 IU/ml (p < 0.0001); TP2-71.4% vs 100%, (p < 0.001), MAB- 235 IU/ml vs 453 IU/ml, (p < 0.05); TP4-95.2% vs 100% (p > 0.05), MAB-1029 IU/ml vs 1538 IU/ml (p < 0.0001); TP5-100% vs 100%, MAB-1542 IU/ml vs 1741IU/ml (p > 0.05); TP6-100% vs 100%, MAB-1961 IU/ml vs 2911 IU/ml (p > 0.05). At TP2, patients aged < 60 years (p < 0.001) were associated with maintaining seropositivity compared to patients > 60 years.ConclusionTwo dose vaccination of haemodialysis patients provided poor nAB levels which improved markedly following 3rd dose vaccination, the effect of which was long- lasting with high nAB levels in both patients and controls detectable at 1 year follow-up.

Relative and Temporal Efficacy of the First and Second Covid 19 Booster Vaccine (3rd And 4th Dose) to Prevent Symptomatic Infection from December 2021 to October 2023 in a General Medicine Office in Toledo (Spain)

Background: The effectiveness of COVID-19 vaccines in preventing serious infection and death is established, but their protection against infection is less certain. Additionally, their effectiveness diminishes over time. Furthermore, the evolution of the effectiveness of different booster doses of the vaccine against COVID-19, to prevent symptomatic infection in real life during the pandemic and the subsequent endemic, is not clearly documented. Objective: To compare the effectiveness of the 3rd and 4th vaccine boosters against COVID-19 in preventing symptomatic COVID-19 infection during both the pandemic and the subsequent endemic phase. Methodology: A comparative secondary analysis of the vaccine’s effectiveness against symptomatic COVID-19 infection (calculated as: 1 – (COVID-19 cases with vaccine doses / COVID-19 cases without vaccine dose) × 100) based on a prospective study from December 2021 to October 2023 in a general medicine office was conducted. The first booster dose was administered with monovalent mRNA vaccines, and the second booster with bivalent mRNA vaccines. Results: From December 2021 to February 2022, the effectiveness of the primer vaccine booster was 60% when administered &gt;= 15 days versus &lt;15 days before infection, and 36% when administered &gt;= 29 days versus &lt; 29 days before infection. From October 2022 to February 2023, the effectiveness of the vaccine’s 4th dose was 84%. From October 2022 to October 2023, the effectiveness of the 4th dose of bivalent mRNA vaccine in preventing reinfections was 30%. Conclusion: In the general practice setting in Toledo, Spain, the effectiveness of the first booster with mRNA vaccines against SARS-CoV-2 primary infection and symptomatic COVID-19 waned over time, but protection remained high with the second bivalent booster. However, the booster vaccine’s effectiveness is more modest in preventing symptomatic reinfections. Overall, completing the booster vaccination is worthwhile.

Non-cross-reactive epitopes dominate the humoral immune response to COVID-19 vaccination - kinetics of plasma antibodies, plasmablasts and memory B cells.

COVID-19 vaccines are highly effective in inducing protective immunity. While the serum antibody response to COVID-19 vaccination has been studied in depth, our knowledge of the underlying plasmablast and memory B cell (Bmem) responses is still incomplete. Here, we determined the antibody and B cell response to COVID-19 vaccination in a naïve population and contrasted it with the response to a single influenza vaccination in a primed cohort. In addition, we analyzed the antibody and B cell responses against the four endemic human coronaviruses (HCoVs). Measurement of specific plasma IgG antibodies was combined with functional analyses of antibody-secreting plasmablasts and Bmems. SARS-CoV-2- and HCoV-specific IgG antibodies were quantified with an in-house bead-based multiplexed immunoassay. The antibody and B cell responses to COVID-19 vaccination reflected the kinetics of a prime-boost immunization, characterized by a slow and moderate primary response and a faster and stronger secondary response. In contrast, the influenza vaccinees possessed robust immune memory for the vaccine antigens prior to vaccination, and the recall vaccination moderately boosted antibody production and Bmem responses. Antibody levels and Bmem responses waned several months after the 2nd COVID-19 vaccination, but were restored upon the 3rd vaccination. The COVID-19 vaccine-induced antibodies mainly targeted novel, non-cross-reactive S1 epitopes of the viral spike protein, while cross-reactive S2 epitopes were less immunogenic. Booster vaccination not only strongly enhanced neutralizing antibodies against an original SARS-CoV-2 strain, but also induced neutralizing antibodies against the Omicron BA.2 variant. We observed a 100% plasma antibody prevalence against the S1 subunits of HCoVs, which was not affected by vaccination. Overall, by complementing classical serology with a functional evaluation of plasmablasts and memory B cells we provide new insights into the specificity of COVID-19 vaccine-induced antibody and B cell responses.

Development of antibody levels and subsequent decline in individuals with vaccine induced and hybrid immunity to SARS-CoV-2

ObjectivesThis study aimed to compare antibody trajectories among individuals with SARS-CoV-2 hybrid and vaccine-induced immunity. MethodsDanish adults receiving three doses of BTN162b2 or mRNA-1237 were included prior to first vaccination (Day 0). SARS-CoV-2 anti-spike IgG levels were assessed before each vaccine dose, at Day 90, Day 180, 28 days after 3rd vaccination (Day 251), Day 365, and prior to 4th vaccination (Day 535). SARS-CoV-2 PCR results were extracted from the national microbiology database. Mixed-effect multivariable linear regression investigated the impact of hybrid-immunity (stratified into 4 groups: no hybrid immunity, PCR+ prior to 3rd dose, PCR+ after 3rd dose and before Day 365, PCR+ after Day 365) on anti-spike IgG trajectories. ResultsA total of 4,936 individuals were included, 47% developed hybrid-immunity. Anti-spike IgG increases were observed in all groups at Day 251, with the highest levels in those PCR+ prior to 3rd dose (Geometric Mean; 535,647AU/mL vs. 374,665AU/mL with no hybrid-immunity, P<0.0001). Further increases were observed in participants who developed hybrid immunity after their 3rd dose. Anti-spike IgG levels declined from Day 251-535 in individuals without hybrid-immunity and in those who developed hybrid-immunity prior to their 3rd dose, with lower rate of decline in those with hybrid-immunity. ConclusionHybrid-immunity results in higher and more durable antibody trajectories in vaccinated individuals.

Recovery from antibody-mediated biliary ductopenia and multiorgan inflammation after COVID-19 vaccination

The coronavirus disease 2019 (COVID-19) pandemic has caused significant morbidity and mortality. Spike messenger RNA (mRNA)–based vaccines against severe acute respiratory syndrome coronavirus 2 may contribute to immune-mediated injuries. Here we present a case of a previously healthy 47-year-old man, who developed progressive jaundice 2 weeks after receiving his 3rd COVID-19 vaccination (1st mRNA-based vaccine). Apart from elevated serum total bilirubin levels (peaked at >70 mg/dL), deteriorating renal (blood urea nitrogen: peak, 108.5 mg/dL; creatinine: peak, 6 mg/dL) and exocrine pancreas (amylase: peak, 1717 U/L; lipase: peak, 5784 U/L) profiles were also seen. Vanishing bile duct syndrome characterized by ductopenia and cholangiocyte vacuolation, positive C4d deposition, and high titer of anti-angiotensin II type 1 receptor antibody consistently explain the overall antibody-mediated pathogenesis resembling antibody-mediated “rejection” in the solid organ transplant setting. Corticosteroids and plasmapheresis were administered, leading to gradual resolution of the symptoms, and the jaundice completely resolved 2 months later. In conclusion, we reported a case of antibody-mediated multiorgan injury after an mRNA COVID-19 vaccine, characterized by severe cholangiopathy. The patient recovered with corticosteroids and plasmapheresis, and long-term follow-up is necessary.

Severe ulcerative colitis induced by COVID-19 vaccination

A 37-year-old woman developed severe colitis with diffuse mucosal erythema and ulcerations throughout the entire colon after the 3rd vaccination of COVID-19. Stool culture was negative, and the pathological findings showed increased lymphoplasmacytic and neutrophilic infiltration in the colonic lamina propria, which were consistent with ulcerative colitis. After the treatment with anti-tumor necrosis factor-α agent, the ulceration markedly improved with development of severe colonic stenosis, which was successfully dilated with endoscopic balloon dilation. In case of COVID-19 vaccination, it should be noted that vaccination could be a trigger for the onset of UC.

The Acceptance of Covid-19 Vaccine in North Sulawesi Community: Prevalance and Risk Factor

Vaccination stands as the sole preventive measure against the transmission of COVID-19. The vaccination rollout in Indonesia comprises three stages: primary vaccinations 1 and 2, along with an additional 3rd or booster vaccination. However, certain regions still exhibit a stage 2 vaccination coverage below 70%. Various factors, including age and gender, impact the acceptance of the Covid-19 vaccine. The objective of this study was to scrutinize the association between age, gender, and the acceptance of Covid-19 vaccination in the jurisdiction of the Kawangkoan Barat Public Health Center. Conducted between February and July 2022, this correlational research involved 400 respondents aged 18 and above. The study variables encompassed age, gender, and vaccination acceptance, assessed through a fill-in sheet. Bivariate data analysis employed the chi-square test, revealing a significant correlation between age and vaccination acceptance. The prevalence ratio (PR) of 1.504 indicated that individuals aged 18-59 years were 1.504 times more likely to have incomplete vaccinations. However, gender did not exhibit a significant correlation with vaccination acceptance. In conclusion, age emerges as a correlated factor influencing the acceptance of Covid-19 vaccination

Restricted Omicron-specific cross-variant memory B-cell immunity after a 3rd dose/booster of monovalent Wuhan-Hu-1-containing COVID-19 mRNA vaccine

The responsiveness/cross-binding of vaccine-induced memory B cells/MBCs to previous and emerging divergent SARS-CoV-2 variants (e.g., Omicron) is understudied. In this longitudinal study subjects receiving two or three doses of monovalent ancestral strain-containing COVID-19 mRNA vaccine were evaluated. In contrast to others, we observed significantly lower frequencies of MBCs reactive to the receptor-binding domain/RBD, the N-terminal domain/NTD, and the S1 of Omicron/BA.1, compared to Wuhan and Delta, even after a 3rd vaccine dose/booster. Our study is a proof of concept that MBC cross-reactivity to variants with greater sequence divergence from the vaccine strain may be overestimated and suggests that these variants may exhibit immune escape with reduced recognition by circulating pre-existing MBCs upon infection.

Modeling of antibody responses to COVID-19 vaccination in patients with rheumatoid arthritis

To construct a model of the antibody response to COVID-19 vaccination in patients with rheumatoid arthritis (RA), and to identify clinical factors affecting the antibody response. A total of 779 serum samples were obtained from 550 COVID-19-naïve RA patients who were vaccinated against COVID-19. Antibody titers for the receptor binding domain (anti-RBD) and nucleocapsid (anti-N) were measured. The time from vaccination, and the log-transformed anti-RBD titer, were modeled using a fractional polynomial method. Clinical factors affecting antibody responses were analyzed by a regression model using generalized estimating equation. The anti-RBD titer peaked at about 2 weeks post-vaccination and decreased exponentially to 36.5% of the peak value after 2 months. Compared with the first vaccination, the 3rd or 4th vaccinations shifted the peaks of anti-RBD antibody response curves significantly upward (by 28-fold [4–195] and 32-fold [4–234], respectively). However, there was no significant shift in the peak from the 3rd vaccination to the 4th vaccination (p = 0.64). Multivariable analysis showed that sulfasalazine increased the vaccine response (by 1.49-fold [1.13–1.97]), but abatacept or JAK inhibitor decreased the vaccine response (by 0.13-fold [0.04–0.43] and 0.44-fold [0.26–0.74], respectively). Age was associated with lower ln [anti-RBD] values (coefficient: − 0.03 [− 0.04 to − 0.02]). In conclusion, the anti-RBD response of RA patients peaked at 2 weeks after COVID-19 vaccination, and then decreased exponentially, with the maximum peak increase observed after the 3rd vaccination. The antibody response was affected by age and the medications used to treat RA.

Antigen-specific T helper cells and cytokine profiles predict intensity and longevity of cellular and humoral responses to SARS-CoV-2 booster vaccination.

Pre-existent pools of coronavirus-specific or cross-reactive T cells were shown to shape the development of cellular and humoral immune responses after primary mRNA vaccination against SARS-CoV-2. However, the cellular determinants of responses to booster vaccination remain incompletely understood. Therefore, we phenotypically and functionally characterized spike antigen-specific T helper (Th) cells in healthy, immunocompetent individuals and correlated the results with cellular and humoral immune responses to BNT162b2 booster vaccination over a six-month period. Blood of 30 healthy healthcare workers was collected before, 1, 3, and 6 months after their 3rd BNT162b2 vaccination. Whole blood was stimulated with spike peptides and analyzed using flow cytometry, a 13-plex cytokine assay, and nCounter-based transcriptomics. Spike-specific IgG levels at 1 month after booster vaccination correlated with pre-existing CD154+CD69+IFN-γ+CD4+ effector memory cells as well as spike-induced IL-2 and IL-17A secretion. Early post-booster (1-month) spike IgG levels (r=0.49), spike-induced IL‑2 (r=0.58), and spike-induced IFN‑γ release (r=0.43) correlated moderately with their respective long-term (6-month) responses. Sustained robust IgG responses were significantly associated with S-specific (CD69+±CD154+±IFN-γ+) Th-cell frequencies before booster vaccination (p=0.038), especially double/triple-positive type-1 Th cells. Furthermore, spike IgG levels, spike-induced IL‑2 release, and spike-induced IFN‑γ release after 6 months were significantly associated with increased IL‑2 & IL‑4, IP‑10 & MCP1, and IFN‑γ & IP‑10 levels at 1 month post-booster, respectively. On the transcriptional level, induction of pathways associated with both T-cell proliferation and antigen presentation was indicative of sustained spike-induced cytokine release and spike-specific IgG production 6 months post-booster. Using support vector machine models, pre-booster spike-specific T-cell frequencies and early post-booster cytokine responses predicted sustained (6-month) responses with F1 scores of 0.80-1.00. In summary, spike-specific Th cells and T-cellular cytokine signatures present before BNT162b2 booster vaccination shape sustained adaptive cellular and humoral responses post-booster. Functional T-cell assays might facilitate early identification of potential non-responders.

Safety and immunogenicity of different booster vaccination schemes for COVID-19 used in El Salvador.

The effectiveness of coronavirus disease 2019 (COVID-19) vaccination schemes and the combination of vaccines of various platforms for administering booster doses is still being studied since it will depend on the population's response to vaccines. We aimed to evaluate the safety, protection, and immunogenicity of the Salvadorean population's third dose booster COVID-19 vaccine and the potential benefit of homologous vs. heterologous regimens. This is an analytical observational cohort study in a population aged 18 to 65 years that was primarily vaccinated with AstraZeneca, Sinovac, or Pfizer/BioNTech. Volunteers were recruited (n=223) and followed up for 3 months after receiving the 3rd vaccine (BNT162b2) as a booster. Adverse reactions were monitored, serum anti-spike immunoglobulin G (IgG) was assessed by chemiluminescence, and a polymerase chain reaction was carried out when subjects developed clinical signs. The cohorts finally included 199 participants, and we observed only mild adverse effects in all cohorts. A significant increase in specific IgG levels was found after the booster dose in all cohorts. The heterologous scheme with Sinovac showed the greatest increase in antibody titer, and a decrease was observed in all participants after 3 months. During the follow-up period, 30 participants showed symptomatology compatible with COVID-19, but only four were laboratory-confirmed and they showed mild clinical signs. These findings indicate that the booster doses used were safe and promoted an immediate increase in immunogenicity, which decreased over time. The heterologous regimen showed stronger immunogenicity compared to the messenger RNA-based homologous scheme.

Immunogenicity assessment of elder hepatocellular carcinoma patients after inactivated whole-virion SARS-CoV-2 vaccination

ABSTRACTBackgroundResearch on immunogenicity after 3rd SARS-CoV-2 vaccine in elder hepatocellular carcinoma (HCC) was limited. This study aimed to investigate the efficacy and influencing factors of inactivated SARS-CoV-2 vaccine in elder HCC.Research design and methodsWe assessed total antibodies, anti-RBD IgG, and neutralizing antibodies (NAb) toward SARS-CoV-2 wild type (WT) as well as BA.4/5 in 304 uninfected HCC, 147 matched healthy control (HC), and 53 SARS-CoV-2 infected HCC, all aged over 60 years. The levels of antibodies were compared in the period 7–90, 91–180, and >180 days after 2nd or 3rd vaccination, respectively.ResultsHCC had lower seropositivity than HC after 2nd dose (total antibodies, 64% vs. 92%, P < 0.0001; anti-RBD IgG, 50% vs. 77%, P < 0.0001). But 3rd dose can efficaciously close the gap (total antibodies, 96% vs. 100%, P = 0.1212; anti-RBD IgG: 87% vs. 87%, P > 0.9999). Booster effect of 3rd dose can persist >180 days in HCC (2nd vs. 3rd: total antibodies, 0.60 vs. 3.20, P < 0.0001; anti-RBD IgG, 13.86 vs. 68.85, P < 0.0001; WT NAb, 11.70 vs. 22.47, P < 0.0001). Vaccinated HCC had more evident humoral responses than unvaccinated ones after infection (total antibodies: 3.85 vs. 3.20, P < 0.0001; anti-RBD IgG: 910.92 vs. 68.85, P < 0.0001; WT NAb: 96.09 vs. 22.47, P < 0.0001; BA.4/5 NAb: 86.53 vs. 5.59, P < 0.0001).ConclusionsOur findings highlight the booster effect and protective role of 3rd dose. Our results could provide a theoretical foundation for informing decisions regarding SARS-CoV-2 vaccination in elder HCC.

Rapid transient and longer-lasting innate cytokine changes associated with adaptive immunity after repeated SARS-CoV-2 BNT162b2 mRNA vaccinations.

Cytokines and chemokines play an important role in shaping innate and adaptive immunity in response to infection and vaccination. Systems serology identified immunological parameters predictive of beneficial response to the BNT162b2 mRNA vaccine in COVID-19 infection-naïve volunteers, COVID-19 convalescent patients and transplant patients with hematological malignancies. Here, we examined the dynamics of the serum cytokine/chemokine responses after the 3rd BNT162b2 mRNA vaccination in a cohort of COVID-19 infection-naïve volunteers. We measured serum cytokine and chemokine responses after the 3rd dose of the BNT162b2 mRNA (Pfizer/BioNtech) vaccine in COVID-19 infection-naïve individuals by a chemiluminescent assay and ELISA. Anti-Spike binding antibodies were measured by ELISA. Anti-Spike neutralizing antibodies were measured by a pseudotype assay. Comparison to responses found after the 1st and 2nd vaccinations showed persistence of the coordinated responses of several cytokine/chemokines including the previously identified rapid and transient IL-15, IFN-γ, CXCL10/IP-10, TNF-α, IL-6 signature. In contrast to the transient (24hrs) effect of the IL-15 signature, an inflammatory/anti-inflammatory cytokine signature (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, CXCL8/IL-8, IL-1Ra) remained at higher levels up to one month after the 2nd and 3rd booster vaccinations, indicative of a state of longer-lasting innate immune change. We also identified a systemic transient increase of CXCL13 only after the 3rd vaccination, supporting stronger germinal center activity and the higher anti-Spike antibody responses. Changes of the IL-15 signature, and the inflammatory/anti-inflammatory cytokine profile correlated with neutralizing antibody levels also after the 3rd vaccination supporting their role as immune biomarkers for effective development of vaccine-induced humoral responses. These data revealed that repeated SARS-Cov-2 BNT162b2 mRNA vaccination induces both rapid transient as well as longer-lasting systemic serum cytokine changes associated with innate and adaptive immune responses. Clinicaltrials.gov, identifier NCT04743388.

2338. Robust and Persistent B Cell Responses Following Third Dose SARS-CoV-2 Vaccine Determine Protection from COVID-19

Abstract Background The immunological memory to SARS-CoV-2 (SCV-2) vaccination has multiple components, with robust antibody (Ab) and B cell responses demonstrated post vaccination. The extent and persistence of T cell responses to vaccination remains unclear. We explored SCV-2 specific Ab, B cell and T cell responses to 3rd dose vaccine and their relationship to incident COVID-19. Methods In plasma from adults enrolled in a multicentre prospective cohort, sampled before, 14 days and 10 months post 3rd dose vaccine (BNT162b2) we measured anti-SCV-2 receptor binding domain (RBD) Ab by electrochemiluminescence assays. Subjects reported incident COVID-19 that occurred post vaccination. In a subanalysis, we assessed SCV-2-specific plasma cell, memory B cell and T cell responses in peripheral blood mononuclear cells after stimulation with wild type (WT) RBD, WT full Spike antigen, Omicron RBD and Omicron S1 antigens by ELISpot (Mabtech ELISpot, Sweden, Fig 1). We compared between-group differences in immunological outcomes by incident infection by Wilcoxon signed rank or Mann–Whitney U tests. Data are median (IQR) unless specified. Results Of 132 subjects (age 43 [32-50], 81% female (Table 1), 47 (36%) reported incident SCV-2 infection at 18 (16-21) weeks post 3rd vaccine. 76 subjects contributed to the cellular immunity subanalysis [23 of whom provided additional samples 10 months post vaccine (Table 1)]. RBD titres and B cell responses increased significantly 2 weeks post 3rd vaccine (Fig 2, p&amp;lt; 0.001), with RBD titres and WT-specific memory B cell responses remaining significantly higher than pre-booster vaccine levels at 10 months (Fig 2, p&amp;lt; 0.001). In contrast, there was no significant difference in T cell responses at two weeks or 10 months post 3rd dose vaccine (Fig 2). There was no difference in 2-week post vaccine RBD or T cell responses in those with and without incident SCV-2 infection. However, those with incident infection had significantly lower WT RBD-specific plasma and memory B cell levels (Table 2, all p&amp;lt; 0.05). Conclusion 3rd dose vaccination induced robust antibody and B cell responses which persist at 10 months, but not T cell responses. Higher memory B cell responses post vaccination, rather than circulating antibody titres or T cells, are associated with protection from subsequent infection. Disclosures Oliver A. Cornely, MD PhD, DZIF: Advisor/Consultant|DZIF: Board Member|DZIF: Grant/Research Support|DZIF: Honoraria|DZIF: Stocks/Bonds

Immunogenicity and reactogenicity of a first booster with BNT162b2 or full-dose mRNA-1273: A randomised VACCELERATE trial in adults ≥75 years (EU-COVAT-1)

BackgroundVaccination remains crucial for protection against severe SARS-CoV-2 infection, especially for people of advanced age, however, optimal dosing regimens are as yet lacking. MethodsEU-COVAT-1-AGED Part A is a randomised controlled, adaptive, multicentre phase II trial evaluating safety and immunogenicity of a 3rd vaccination (1st booster) in individuals ≥75 years. Fifty-three participants were randomised to full-doses of either mRNA-1273 (Spikevax®, 100 µg) or BNT162b2 (Comirnaty®, 30 µg). The primary endpoint was the rate of 2-fold circulating antibody titre increase 14 days post-vaccination measured by quantitative electrochemiluminescence (ECL) immunoassay, targeting RBD region of Wuhan wild-type SARS-CoV-2. Secondary endpoints included the changes in neutralising capacity against wild-type and 25 variants of concern at 14 days and up to 12 months. Safety was assessed by monitoring of solicited adverse events (AEs) for seven days after on-study vaccination. Unsolicited AEs were collected until the end of follow-up at 12 months, SAEs were pursued for a further 30 days. ResultsBetween 08th of November 2021 and 04th of January 2022, 53 participants ≥75 years received a COVID-19 vaccine as 1st booster. Fifty subjects (BNT162b2 n = 25/mRNA-1273 n = 25) were included in the analyses for immunogenicity at day 14.The primary endpoint of a 2-fold anti-RBD IgG titre increase 14 days after vaccination was reached for all subjects. A 3rd vaccination of full-dose mRNA-1273 provided higher anti-RBD IgG titres (Geometric mean titre) D14 mRNA-127310711 IU/mL (95 %-CI: 8003;14336) vs. BNT162b2: 7090 IU/mL (95 %-CI: 5688;8837). We detected a pattern showing higher neutralising capacity of full-dose mRNA-1273 against wild-type as well as for 23 out of 25 tested variants. InterpretationThird doses of either BNT162b2 or mRNA-1273 provide substantial circulating antibody increase 14 days after vaccination. Full-dose mRNA-1273 provides higher antibody levels with an overall similar safety profile for people ≥75 years. FundingThis trial was funded by the European Commission (Framework Program HORIZON 2020).

Effectiveness of COVID-19 vaccination against COVID-19 specific and all-cause mortality in older Australians: a population based study

Few studies have examined effectiveness of COVID-19 vaccines against COVID-19 and all-cause mortality across different pandemic periods in2022. We used linked whole-of-population data from the 2021 Australian Census, Australian Immunisation Register, death registrations and other national datasets including migration data. Among 3.8 million adults aged 65+ years and >170,000 aged care residents, we used survival analysis to estimate vaccine effectiveness (VE) against COVID-19 specific mortality and all-cause mortality, by vaccine dose and time since receipt, adjusted for age, sex and other factors. We also estimated absolute COVID-19 mortality rates. From January-May 2022 (Omicron BA.1/2), 3250 COVID-19 deaths occurred; from June-November (Omicron BA.4/5) 3185 COVID-19 deaths occurred. During January-May, VE of a 3rd COVID-19 vaccine dose within 3 months was 93% (95% CI 93-94%) whilst VE of a 2nd dose >6 months since receipt was 34% (26-42%). During June-November, VE of a 4th COVID-19 vaccine dose within 3 months was 84% (82-86%) whilst VE of a 3rd dose >6 months since receipt was 56% (50-62%). VE estimates for aged care residents were similar, but absolute risk reductions were substantially greater. During June-November 2022, for all-cause mortality, VE of a 4th dose within 3 months was 58% (56-59%) whilst VE of a 3rd dose >6 months since receipt was 19% (16-22%). COVID-19 vaccination is highly effective against COVID-19 mortality among older adults although effectiveness wanes with time since the last dose. Our findings emphasise the importance of continuing to administer booster doses, particularly to those at highest risk. This study was funded by the Health Economics Research Division in the Australian Government Department of Health and Aged Care.

B-071 Comparison of Humoral and Cellular Immune Responses Between ChAd-BNT Heterologous Vaccination and BNT-BNT Homologous Vaccination Following the third BNT Dose: A Prospective Cohort Study

Abstract Background The differential immune responses after two additional BNT162b2 (BNT) doses between ChAdOx1 nCoV-10 (ChAd)-primed and BNT-primed groups have not been elucidated. The aim of this study was to compare vaccine-induced humoral and cellular immune responses and evaluate breakthrough infection between the two vaccination strategies. Methods In 221 healthy subjects (111 in the ChAd group), longitudinal immune responses were monitored at 3, 4, and 6 months after the 2nd dose and 1, 3, and 6 months after the 3rd dose. Humoral immunity was measured by two fully automated chemiluminescent immunoassays (Elecsys and Abbott) and a surrogate virus neutralization test (sVNT). Cellular immunity was assessed by two interferon-γ (IFN-γ) release assays (QuantiFERON SARS-CoV-2 and Covi-FERON). Results After the 2nd dose of BNT vaccination, total antibody levels were higher in the ChAd group, but IgG antibody and sVNT results were higher in the BNT group. Following the 3rd dose vaccination, binding antibody titers were significantly elevated in both groups (ChAD-BNT; 15.4 to 17.8-fold, BNT-BNT; 22.2 to 24.6-fold), and the neutralizing capacity was increased by 1.3-fold in both cohorts. The ChAd-BNT group had lower omicron neutralization positivity than the BNT-BNT group (P = 0.001) at 6 months after the 3rd dose. Cellular responses to the spike antigen also showed 1.7 to 3.0-fold increases after the 3rd dose, which gradually declined to the levels equivalent to before the 3rd vaccination. The ChAd cohort tended to have higher IFN-γ level than the BNT cohort for 3–6 months after the 2nd and 3rd doses. The frequency of breakthrough infection was higher in the ChAd group (44.8%) than in the BNT group (28.1%) (P = 0.0219). Breakthrough infection induced increased humoral responses in both groups, and increase of cellular response was significant in the ChAd group. Conclusion Our study showed differential humoral and cellular immune responses between ChAd-BNT-BNT heterologous and BNT-BNT-BNT homologous vaccination cohorts. The occurrence of low antibody levels in the ChAd-primed cohort in the humoral immune response may be associated with an increased incidence of breakthrough infections. Further studies are needed on the benefits of enhanced cellular immunity in ChAd-primed cohorts.

Case study of a 2022 pertussis epidemic in the Baoro sub-prefecture (Central African Republic)

ObjectiveThe objective of this survey was to describe epidemiological characteristics and evaluate vaccine effectiveness against pertussis in the sub-prefecture of Baoro (Central African Republic). MethodWe conducted a case control study from June to July 2022 in the sub-prefecture of Baoro in the district of Baour-Baoro. Community-based definitions of surveillance were applied to include cases and controls. ResultsAll in all, 143 confirmed and suspected cases and 166 controls were enrolled in this investigation. The epidemic had affected 12 neighborhoods and 9 villages. The village of Bugbassem alone had 32 patients, and 50% of the patients lived in rural areas. The age groups of 12 to 59 months accounted for 58% of cases. Patients were female in 54% of cases (p = 0.8). The attack rate among unvaccinated patients (65%) was higher than that of vaccinated patients (40%), while 15% (N = 21) of children were hospitalized with no recorded deaths. Pentavalent 3rd dose vaccination coverage was 49% in controls versus 33% in cases. Vaccination provided a significant protective effect (Odds Ratio = 0.3; 95% CI: 0.2–0.6). All told, vaccine efficacy against pertussis was 38%. ConclusionPertussis is a re-emerging disease currently occurring as a result of low pertussis vaccination coverage. It strongly affects rural areas with low vaccination rates. Vaccination strategy requires reinforcement in rural areas.