Safety, reactogenicity, and immunogenicity of Ad26.COV2.S as homologous or heterologous COVID-19 booster vaccination: Results of a randomized, double-blind, phase 2 trial.

COVID-19 vaccine boosters may optimize durability of protection against variants of concern (VOCs). In this randomized, double-blind, phase 2 trial, participants received 3 different dose levels of an Ad26.COV2.S booster (5 × 1010 vp [viral particles], 2.5 × 1010 vp, or 1 × 1010 vp) ≥6 months post-primary vaccination with either single-dose Ad26.COV2.S (homologous boost; n = 774) or 2-dose BNT162b2 (heterologous boost; n = 758). Primary endpoints were noninferiority of neutralizing antibody responses at Day 15 post-boost versus Day 29 post-primary vaccination. Secondary endpoints included reactogenicity/safety and neutralizing antibody responses to VOCs. All primary endpoints passed prespecified hierarchical noninferiority criteria by Day 15 post-boost. Geometric mean increases in neutralizing antibody titers against the D614G reference strain ranged from 5.5 to 6.8 at Day 15 for homologous boosting and 12.6 to 22.0 for heterologous boosting. For VOCs, heterologous boosting elicited higher neutralizing antibody responses than homologous boosting. Neutralizing antibody responses were dose-dependent and durable for ≥6 months post-boost. More solicited systemic adverse events occurred following heterologous versus homologous boosting. Trial Registration:ClinicalTrials.gov Identifier: NCT04999111.

Establishment of human post-vaccination SARS-CoV-2 standard reference sera.

There is a critical need to understand the effectiveness of serum elicited by different SARS-CoV-2 vaccines against SARS-CoV-2 variants. We describe the generation of reference reagents comprised of post-vaccination sera from recipients of different primary vaccines with or without different vaccine booster regimens in order to allow standardized characterization of SARS-CoV-2 neutralization in vitro. We prepared and pooled serum obtained from donors who received a either primary vaccine series alone, or a vaccination strategy that included primary and boosted immunization using available SARS-CoV-2 mRNA vaccines (BNT162b2, Pfizer and mRNA-1273, Moderna), replication-incompetent adenovirus type 26 vaccine (Ad26.COV2·S, Johnson and Johnson), or recombinant baculovirus-expressed spike protein in a nanoparticle vaccine plus Matrix-M adjuvant (NVX-CoV2373, Novavax). No subjects had a history of clinical SARS-CoV-2 infection, and sera were screened with confirmation that there were no nucleocapsid antibodies detected to suggest natural infection. Twice frozen sera were aliquoted, and serum antibodies were characterized for SARS-CoV-2 spike protein binding (estimated WHO antibody binding units/ml), spike protein competition for ACE-2 binding, and SARS-CoV-2 spike protein pseudotyped lentivirus transduction. These reagents are available for distribution to the research community (BEI Resources), and should allow the direct comparison of antibody neutralization results between different laboratories. Further, these sera are an important tool to evaluate the functional neutralization activity of vaccine-induced antibodies against emerging SARS-CoV-2 variants of concern. IMPORTANCE: The explosion of COVID-19 demonstrated how novel coronaviruses can rapidly spread and evolve following introduction into human hosts. The extent of vaccine- and infection-induced protection against infection and disease severity is reduced over time due to the fall in concentration, and due to emerging variants that have altered antibody binding regions on the viral envelope spike protein. Here, we pooled sera obtained from individuals who were immunized with different SARS-CoV-2 vaccines and who did not have clinical or serologic evidence of prior infection. The sera pools were characterized for direct spike protein binding, blockade of virus-receptor binding, and neutralization of spike protein pseudotyped lentiviruses. These sera pools were aliquoted and are available to allow inter-laboratory comparison of results and to provide a tool to determine the effectiveness of prior vaccines in recognizing and neutralizing emerging variants of concern.

Safety and immunogenicity of Ad26.COV2.S in adults: A randomised, double-blind, placebo-controlled Phase 2a dose-finding study.

BACKGROUND: A single dose of Ad26.COV2.S is well-tolerated and effective in preventing moderate-to-severe disease outcomes due to COVID-19. We evaluated the impact of dose level, number of doses, and dose interval on immunogenicity, reactogenicity, and safety of Ad26.COV2.S in adults. Anamnestic responses were also explored. METHODS: This randomised, double-blind, placebo-controlled, Phase 2a study was conducted in adults aged 18-55 years and ≥ 65 years (NCT04535453). Four dose levels (1.25 × 1010, 2.5 × 1010, 5 × 1010, and 1 × 1011 viral particles [vp], single and 2-dose schedules, and dose intervals of 56 and 84 days, were assessed. Four or 6 months post-primary vaccination, Ad26.COV2.S 1.25 × 1010 vp was given to evaluate anamnestic responses. Humoral and cell-mediated immune responses were measured. Reactogenicity and safety were assessed in all participants. RESULTS: All Ad26.COV2.S schedules induced humoral responses with evidence of a dose response relationship. A single dose of Ad26.COV2.S (5 × 1010 vp) induced antibody and cellular immune responses that persisted for up to at least 6 months. In the 2-dose regimens, antibody responses were higher than 1-dose regimens at comparable dose levels, and the magnitude of the immune response increased when the interval between doses was increased (84 days vs 56 days). Rapid, marked immune responses were observed in all groups after vaccine antigen exposure indicating immune memory. Durable immune responses were observed in all groups for up to at least 6 months post-antigen exposure. Strong and consistent correlations between neutralising and binding antibodies were observed CD4 + and CD8 + T cell responses were similar after all regimens. Reactogenicity within 7 days post-vaccination tended to be dose-related. CONCLUSION: The study supports the primary, single dose schedule with Ad26.COV2.S at 5 × 1010 vp and homologous booster vaccination after a 6 month interval. Rapid and marked responses to vaccine antigen exposure indicate induction of immune memory by 1- and 2-dose primary vaccination.

Heterologous Ad26/Ad5 adenovirus-vectored vaccines elicited SARS-CoV-2-specific antibody responses with potent Fc activities.

Introduction: Antibodies against the SARS-CoV-2 spike protein are a critical immune determinant for protection against the virus. While virus neutralization is a key function of spike-specific antibodies, antibodies also mediate Fc-dependent activities that can play a role in protection or pathogenesis. Methods: This study characterized serum antibody responses elicited after two doses of heterologous adenovirus-vectored (Ad26/ Ad5) vaccines. Results: Vaccine-induced antibody binding titers and Fc-mediated functions decreased over six months, while neutralization titers remained stable. Comparison of antibody isotypes elicited after Ad26/Ad5 vs. LNP-mRNA vaccination and after infection showed that anti-spike IgG1 were dominant and produced to high levels in all groups. The Ad26/Ad5 vaccines also induced IgG4 but not IgG2 and IgG3, whereas the LNP-mRNA vaccines elicited a full Ig spectrum (IgM, IgG1-4, IgA1-2). Convalescent COVID-19 patients had mainly IgM and IgA1 alongside IgG1. Despite these differences, the neutralization potencies against early variants were similar. However, both vaccine groups had antibodies with greater Fc potencies of binding complement and Fcg receptors than the COVID-19 group. The Ad26/Ad5 group also displayed a greater potency of RBD-specific antibody-mediated cellular phagocytosis. Discussion: Antibodies with distinctive quality were induced by different vaccines and infection. The data imply the utility of different vaccine platforms to elicit antibody responses with fine-tuned Fc activities.

The single-dose Janssen Ad26.COV2.S COVID-19 vaccine elicited robust and persistent anti-spike IgG antibody responses in a 12-month Ugandan cohort.

Introduction: The study investigation examined the immune response to the Janssen Ad26.COV2.S COVID-19 vaccine within a Ugandan cohort, specifically targeting antibodies directed against spike (S) and nucleocapsid (N) proteins. We aimed to examine the durability and robustness of the induced antibody response while also assessing occurrences of breakthrough infections and previous anti-Spike seropositivity to SARS-CoV-2. Methods: The study included 319 specimens collected over 12 months from 60 vaccinees aged 18 to 64. Binding antibodies were quantified using a validated ELISA method to measure SARS-CoV-2-specific IgG, IgM, and IgA levels against the S and N proteins. Results: The results showed that baseline seropositivity for S-IgG was high at 67%, increasing to 98% by day 14 and consistently stayed above 95% for up to 12 months. However, S-IgM responses remained suboptimal. A raised S-IgA seropositivity rate was seen that doubled from 40% at baseline to 86% just two weeks following the initial vaccine dose, indicating sustained and robust peripheral immunity. An increase in N-IgG levels at nine months post-vaccination suggested breakthrough infections in eight cases. Baseline cross-reactivity influenced spike-directed antibody responses, with individuals harbouring S-IgG antibodies showing notably higher responses. Discussion: Robust and long lasting vaccine and infection-induced immune responses were observed, with significant implications for regions where administering subsequent doses poses logistical challenges.

Heterologous Ad26.COV2.S booster after primary BBIBP-CorV vaccination against SARS-CoV-2 infection: 1-year follow-up of a phase 1/2 open-label trial.

BACKGROUND: Inactivated whole-virus vaccination elicits immune responses to both SARS-CoV-2 nucleocapsid (N) and spike (S) proteins, like natural infections. A heterologous Ad26.COV2.S booster given at two different intervals after primary BBIBP-CorV vaccination was safe and immunogenic at days 28 and 84, with higher immune responses observed after the longer pre-boost interval. We describe booster-specific and hybrid immune responses over 1 year. METHODS: This open-label phase 1/2 study was conducted in healthy Thai adults aged ≥ 18 years who had completed primary BBIBP-CorV primary vaccination between 90-240 (Arm A1; n = 361) or 45-75 days (Arm A2; n = 104) before enrolment. All received an Ad26.COV2.S booster. We measured anti-S and anti-N IgG antibodies by Elecsys®, neutralizing antibodies by SARS-CoV-2 pseudovirus neutralization assay, and T-cell responses by quantitative interferon (IFN)-γ release assay. Immune responses were evaluated in the baseline-seronegative population (pre-booster anti-N < 1.4 U/mL; n = 241) that included the booster-effect subgroup (anti-N < 1.4 U/mL at each visit) and the hybrid-immunity subgroup (anti-N ≥ 1.4 U/mL and/or SARS-CoV-2 infection, irrespective of receiving non-study COVID-19 boosters). RESULTS: In Arm A1 of the booster-effect subgroup, anti-S GMCs were 131-fold higher than baseline at day 336; neutralizing responses against ancestral SARS-CoV-2 were 5-fold higher than baseline at day 168; 4-fold against Omicron BA.2 at day 84. IFN-γ remained approximately 4-fold higher than baseline at days 168 and 336 in 18-59-year-olds. Booster-specific responses trended lower in Arm A2. In the hybrid-immunity subgroup at day 336, anti-S GMCs in A1 were 517-fold higher than baseline; neutralizing responses against ancestral SARS-CoV-2 and Omicron BA.2 were 28- and 31-fold higher, respectively, and IFN-γ was approximately 14-fold higher in 18-59-year-olds at day 336. Durable immune responses trended lower in ≥ 60-year-olds. CONCLUSION: A heterologous Ad26.COV2.S booster after primary BBIBP-CorV vaccination induced booster-specific immune responses detectable up to 1 year that were higher in participants with hybrid immunity. CLINICAL TRIALS REGISTRATION: NCT05109559.

COVID-19 Vaccine-Associated Uveitis in Patients With a History of Uveitis.

Importance: Understanding the potential risk of uveitis recurrence after COVID-19 vaccination in individuals with a history of uveitis is crucial for vaccination strategies and clinical monitoring. Objective: To investigate the risk of uveitis recurrence after COVID-19 vaccination in a cohort of individuals with a history of uveitis. Design, Setting, and Participants: This retrospective population-based cohort study included individuals diagnosed with uveitis between January 1, 2015, and February 25, 2021, in South Korea. After excluding individuals without COVID-19 vaccination or with SARS-CoV-2 infection, individuals with a history of uveitis who had received at least 1 dose of a messenger RNA (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) or adenovirus vector-based (ChAdOx1 [AstraZeneca] or Ad26.COV2.S [Janssen]) COVID-19 vaccine were included. Data were analyzed from February 26, 2021, to December 31, 2022. Exposure: Demographic and clinical data, along with vaccination details, were retrieved from the Korean National Health Insurance Service and Korea Disease Control and Prevention Agency databases. Main Outcomes and Measures: Outcomes of interest were incidence and risk of postvaccination uveitis in association with different COVID-19 vaccines and periods before and after COVID-19 vaccination. Uveitis was categorized by onset (early, within 30 days, or delayed) and type (anterior or nonanterior). Hazard ratios (HRs) with 95% CIs were calculated to evaluate the risk of uveitis following COVID-19 vaccination, stratified according to vaccine type and vaccination period. Results: Of 543 737 individuals with history of uveitis, 473 934 individuals (mean [SD] age, 58.9 [17.4] years; 243 127 [51.3] female) had documented COVID-19 vaccination and were included in analysis. The cumulative incidence of postvaccination uveitis was 8.6% at 3 months, 12.5% at 6 months, and 16.8% at 1 year, predominantly of the anterior type. Variations in the risk of postvaccination uveitis were observed across different vaccines and intervaccination periods. The risk of early postvaccination uveitis was increased for individuals receiving the BNT162b2 (HR, 1.68; 95% CI, 1.52-1.86), mRNA-1273 (HR, 1.51; 95% CI, 1.21-1.89), ChAdOx1 (HR, 1.60; 95% CI, 1.43-1.79), and Ad26.COV2.S (HR, 2.07; 95% CI, 1.40-3.07) vaccines. The risk of uveitis was higher particularly between the first and second vaccination doses (HR, 1.64; 95% CI, 1.55-1.73). Conclusions and Relevance: These findings suggest that there was an elevated risk of uveitis following COVID-19 vaccination, with the vaccine type and period mediating this risk. For individuals with a history of uveitis, clinicians should consider the potential risk of uveitis recurrence in vaccination strategies and clinical monitoring.

Polymyalgia rheumatica and giant cell arteritis following COVID-19 vaccination: Results from a nationwide survey.

We conducted a national in-depth analysis including pharmacovigilance reports and clinical study to assess the reporting rate (RR) and to determine the clinical profile of polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) in COVID-19-vaccinated individuals. First, based on the French pharmacovigilance database, we estimated the RR of PMR and GCA cases in individuals aged over 50 who developed their initial symptoms within one month of receiving the BNT162b2 mRNA, mRNA-1273, ChAdOx1 nCoV-19, and Ad26.COV2.S vaccines. We then conducted a nationwide survey to gather clinical profiles, therapeutic management, and follow-up data from individuals registered in the pharmacovigilance study. A total of 70 854 684 COVID-19 vaccine doses were administered to 25 260 485 adults, among which, 179 cases of PMR (RR 7. 1 cases/1 000 000 persons) and 54 cases of GCA (RR 2. 1 cases/1 000 000 persons) have been reported. The nationwide survey allowed the characterization of 60 PMR and 35 GCA cases. Median time to the onset of first symptoms was 10 (range 2-30) and 7 (range 2-25) days for PMR and GCA, respectively. Phenotype, GCA-related ischemic complications and -large vessel vasculitis as well as therapeutic management and follow-up seemed similar according to the number of vaccine shots received and when compared to the literature data of unvaccinated population. Although rare, the short time between immunization and the onset of first symptoms of PMR and GCA suggests a temporal association. Physician should be aware of this potential vaccine-related phenomenon.

Risk of encephalitis and meningitis after COVID-19 vaccination in South Korea: a self-controlled case series analysis.

BACKGROUND: Several neurological manifestations shortly after a receipt of coronavirus infectious disease 2019 (COVID-19) vaccine have been described in the recent case reports. Among those, we sought to evaluate the risk of encephalitis and meningitis after COVID-19 vaccination in the entire South Korean population. METHODS: We conducted self-controlled case series (SCCS) analysis using the COVID-19 immunization record data from the Korea Disease Control Agency between February 2021 and March 2022, linked with the National Health Insurance Database between January 2021 and October 2022. We retrieved all medical claims of adults aged 18 years or older who received at least one dose of COVID-19 vaccines (BNT162b2, mRNA-1273, ChAdOx1-S, or Ad26.COV2.S), and included only those who had a diagnosis record for encephalitis or meningitis within the 240-day post-vaccination period. With day 0 defined as the date of vaccination, risk window was defined as days 1-28 and the control window as the remainder period excluding the risk windows within the 240-day period. We used conditional Poisson regression to estimate the incidence rate ratios (IRR) with 95% confidence intervals (CI), stratified by dose and vaccine type. RESULTS: From 129,956,027 COVID-19 vaccine doses administered to 44,564,345 individuals, there were 251 and 398 cases of encephalitis and meningitis during the risk window, corresponding to 1.9 and 3.1 cases per 1 million doses, respectively. Overall, there was an increased risk of encephalitis in the first 28 days of COVID-19 vaccination (IRR 1.26; 95% CI 1.08-1.47), which was only significant after a receipt of ChAdOx1-S (1.49; 1.03-2.15). For meningitis, no increased risk was observed after any dose of COVID-19 vaccine (IRR 1.03; 95% CI 0.91-1.16). CONCLUSIONS: Our findings suggest an overall increased risk of encephalitis after COVID-19 vaccination. However, the absolute risk was small and should not impede COVID-19 vaccine confidence. No significant association was found between the risk of meningitis and COVID-19 vaccination.

Quantifying how single dose Ad26.COV2.S vaccine efficacy depends on Spike sequence features.

In the ENSEMBLE randomized, placebo-controlled phase 3 trial (NCT04505722), estimated single-dose Ad26.COV2.S vaccine efficacy (VE) was 56% against moderate to severe-critical COVID-19. SARS-CoV-2 Spike sequences were determined from 484 vaccine and 1,067 placebo recipients who acquired COVID-19. In this set of prespecified analyses, we show that in Latin America, VE was significantly lower against Lambda vs. Reference and against Lambda vs. non-Lambda [family-wise error rate (FWER) p < 0.05]. VE differed by residue match vs. mismatch to the vaccine-insert at 16 amino acid positions (4 FWER p < 0.05; 12 q-value ≤ 0.20); significantly decreased with physicochemical-weighted Hamming distance to the vaccine-strain sequence for Spike, receptor-binding domain, N-terminal domain, and S1 (FWER p < 0.001); differed (FWER ≤ 0.05) by distance to the vaccine strain measured by 9 antibody-epitope escape scores and 4 NTD neutralization-impacting features; and decreased (p = 0.011) with neutralization resistance level to vaccinee sera. VE against severe-critical COVID-19 was stable across most sequence features but lower against the most distant viruses.

Mortality risk after COVID-19 vaccination: A self-controlled case series study.

BACKGROUND: Although previous studies found no-increased mortality risk after COVID-19 vaccination, residual confounding bias might have impacted the findings. Using a modified self-controlled case series (SCCS) design, we assessed the risk of non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes after primary series COVID-19 vaccination. METHODS: We analyzed all deaths between December 14, 2020, and August 11, 2021, among individuals from eight Vaccine Safety Datalink sites. Demographic characteristics of deaths in recipients of COVID-19 vaccines and unvaccinated individuals were reported. We conducted SCCS analyses by vaccine type and death outcomes and reported relative incidences (RI). The observation period for death spanned from the dates of emergency use authorization to the end of the study period (August 11, 2021) without censoring the observation period upon death. We pre-specified a primary risk interval of 28-day and a secondary risk interval of 14-day after each vaccination dose. Adjusting for seasonality in mortality analyses is crucial because death rates vary over time. Deaths among unvaccinated individuals were included in SCCS analyses to account for seasonality by incorporating calendar month in the models. RESULTS: For Pfizer-BioNTech (BNT162b2), RIs of non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes were below 1 and 95 % confidence intervals (CIs) excluded 1 across both doses and both risk intervals. For Moderna (mRNA-1273), RI point estimates of all outcomes were below 1, although the 95 % CIs of two RI estimates included 1: cardiac-related (RI = 0.78, 95 % CI, 0.58-1.04) and non-COVID-19 cardiac-related mortality (RI = 0.80, 95 % CI, 0.60-1.08) 14 days after the second dose in individuals without pre-existing cancer and heart disease. For Janssen (Ad26.COV2.S), RIs of four cardiac-related death outcomes ranged from 0.94 to 0.98 for the 14-day risk interval, and 0.68 to 0.72 for the 28-day risk interval and 95 % CIs included 1. CONCLUSION: Using a modified SCCS design and adjusting for temporal trends, no-increased risk was found for non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes among recipients of the three COVID-19 vaccines used in the US.

Adverse events following immunization reported with COVID-19 vaccines in Burkina Faso: Analysis of spontaneous reports / Manifestations post-vaccinales indésirables rapportées avec les vaccins anti-COVID-19 au Burkina Faso : analyse des notifications spontanées

The rapid deployment of COVID-19 vaccines to a large proportion of the population requires a focus on safety. However, few studies have assessed the safety of COVID-19 vaccines in Africa. In Burkina Faso, this issue has not yet been addressed. The objective of this study was to contribute to the description of the characteristics of adverse events following immunization (AEFIs) related to COVID-19 vaccines in Burkina Faso. This was a cross-sectional descriptive retrospective study of spontaneous reports of COVID-19 vaccine-related AEFIs recorded in VigiBase® between June 2021 and November 2022 in Burkina Faso. Individual case safety reports (ICSRs) were extracted from VigiBase® using the Anatomical Therapeutic Chemical level 2 (ATC2) code. The proportion of ICSRs according to the reporter's qualification, the reporting rate, the time taken to submit and record ICSRs, and the completeness score were calculated. A total of 973 ICSRs concerned COVID-19 vaccines and represented 32.6% of all 2,988 reports in VigiBase®. Overall, 82.0% of the reporters were nurses/midwives, 7.8% were physicians, 6.7% were pharmacists, and 3.4% were patients. The median time between the onset of AEFIs and the submission of the report to the Pharmacovigilance Center was 180 days (IQR: 136; 281). The median registration time was 188 days (IQR: 149; 286). The mean ICSR completeness score was 0.8 (standard deviation = 0.1). The overall AEFI reporting rate was 27.8 per 100,000 vaccine doses. The AEFI reporting rates for the ChAdOx1-nCoV-19, JNJ 78436735, Elasomeran, Tozinameran, and HB02 vaccines were 454.2, 17.4, 11.0, 10.2, and 0.4 per 100,000 vaccine doses, respectively. The majority of AEFIs were systemic in nature (90.1%). Headache (21.2%), fever (19.4%), and myalgia (11.0%) were the most frequently reported AEFIs. Eighteen cases (1.8%) of serious AEFIs (9 hospitalizations, 4 life threatening, 3 temporary disabilities, and 2 others unspecified) were reported. The majority of AEFIs reported were systemic in nature and mild. However, there have been reports of serious AEFIs. The overall AEFI reporting rate was low. There is a need to strengthen the monitoring of these vaccines to better organize strategies to optimize the adherence of the population of Burkina Faso.

Le déploiement rapide des vaccins anti COVID-19 sur une grande partie de la population nécessite de mettre l'accent sur la sécurité. Cependant, peu d'études ont évalué la sécurité des vaccins anti COVID-19 en Afrique. Au Burkina Faso, cette question n'a pas encore été abordée. La présente étude avait pour objectif de contribuer à la description des caractéristiques des manifestations post-vaccinales indésirables (MAPI) liées aux vaccins anti COVID-19 au Burkina Faso. Il s'est agi d'une étude transversale rétrospective ayant porté sur les notifications de MAPI liées aux vaccins anti COVID-19 enregistrées dans VigiBase® entre juin 2021 et novembre 2022 au Burkina Faso. Les cas individuels de rapports de sécurité (CIRS) ont été extraits de VigiBase® à l'aide du code Anatomical Therapeutic Chemical niveau 2 (ATC2). La proportion de CIRS selon la qualification du notificateur, le taux de notification, le délai de transmission et d'enregistrement des CIRS et le score d'exhaustivité ont été calculés. Au total 973 CIRS concernaient les vaccins anti COVID-19 et représentaient 32,6 % des 2 988 rapports enregistrés dans VigiBase®. La répartition des notifications en fonction de la qualification du notificateur a montré que 82,0 % étaient des infirmiers/sage femmes, 7,8 % des médecins, 6,7 % des pharmaciens et 3,4 % des patients. Le délai médian entre l'apparition des MAPI et la transmission du rapport au Centre de pharmacovigilance était de 180 jours (IQR : 136 ; 281). Le délai médian d'enregistrement était de 188 jours (IQR : 149 ; 286). Le score d'exhaustivité moyen des CIRS était de 0,8 (écart type = 0,1). Le taux global de notifications des MAPI était de 27,8 pour 100 000 doses de vaccins. Les taux de notification des MAPI pour les vaccins ChAdOx1-nCoV-19, JNJ 78436735, Elasomeran, Tozinameran et HB02 étaient de 454,2 ; 17,4 ; 11,0 ; 10,2 et 0,4 pour 100 000 doses, respectivement. La majorité des MAPI était de manifestation systémique (90,1 %). Les céphalées (21,2 %), la fièvre (19,4 %) et les myalgies (11,0 %) étaient les MAPI les plus fréquemment notifiés. Dix-huit cas (1,8 %) de MAPI graves (9 hospitalisations, 4 mises en jeu du pronostic vital, 3 incapacités temporaires et 2 autres non précisés) ont été rapportés. La majorité des cas notifiés dans le cadre de la surveillance des MAPI était de manifestation systémique et de nature bénigne. Néanmoins, des cas de MAPI graves ont été notifiés. Le taux global de notification des MAPI était faible. Il est nécessaire de renforcer la surveillance de ces vaccins pour mieux organiser les stratégies visant à optimiser l'adhésion de la population burkinabé.

Safety of a second homologous Ad26.COV2.S vaccine among healthcare workers in the phase 3b implementation Sisonke study in South Africa.

The Sisonke 2 study provided a homologous boost at least 6 months after administration of the priming dose of Ad26.COV2.S for healthcare workers enrolled on the Sisonke phase 3b implementation study. Safety monitoring was via five reporting sources: (i.) self-report through a web-link; (ii.) paper-based case report forms; (iii.) a toll-free telephonic reporting line; (iv.) healthcare professionals-initiated reports; and (v.) active linkage with National Disease Databases. A total of 2350 adverse events were reported by 2117 of the 240 888 (0.88%) participants enrolled; 1625 of the 2350 reported events are reactogenicity events and 28 adverse events met seriousness criteria. No cases of thrombosis with thrombocytopaenia syndrome were reported; all adverse events including thromboembolic disorders occurred at a rate below the expected population rates apart from one case of Guillain Barre Syndrome and one case of portal vein thrombosis. The Sisonke 2 study demonstrates that two doses of Ad26.COV2.S is safe and well tolerated; and provides a feasible model for national pharmacovigilance strategies for low- and middle-income settings.

Post-marketing active surveillance of Guillain Barré Syndrome following COVID-19 vaccination in persons aged ≥12 years in Italy: A multi-database self-controlled case series study.

BACKGROUND: Recently published studies have reported association of COVID-19 vaccine ChAdOx1-S (Vaxzevria) with Guillain Barré Syndrome (GBS). Less is known about the safety of other COVID-19 vaccines with respect to GBS outcome. This study investigated the association of COVID-19 vaccines with GBS in more than 15 million persons aged ≥12 years in Italy. METHODS: Study population was all individuals aged ≥12 years who received at least one dose of COVID-19 vaccines, admitted to emergency care/hospital for GBS from 27 December 2020-30 September 2021 in Italy. Identification of GBS cases and receipt of at least one dose of mRNA-1273 (Elasomeran), BNT162b2 (Tozinameran), ChAdOx1-S (Vaxzevria) and Ad26.COV2.S (Janssen) through record linkage between regional health care and vaccination registries. Relative Incidence (RI) was estimated Self-controlled case series method adapted to event-dependent exposure using in the 42-day exposure risk period after each dose compared with other observation periods. RESULTS: Increased risk of GBS was found after first (RI = 6.83; 95% CI 2.14-21.85) and second dose (RI = 7.41; 2.35-23.38) of mRNA-1273 and first dose of ChAdOx1-S (RI = 6.52; 2.88-14.77). Analysis by age found an increased risk among those aged≥60 years after first (RI = 8.03; 2.08-31.03) and second dose (RI = 7.71; 2.38-24.97) of mRNA-1273. The first dose of ChAdOx1-S was associated with GBS in those aged 40-59 (RI = 4.50; 1.37-14.79) and in those aged ≥ 60 years (RI = 6.84; 2.56-18.28). CONCLUSIONS: mRNA-1273 and ChAdOx1-S vaccines were associated with an increased risk of GBS however this risk resulted in a small number of excess cases. Limitations were loss of GBS outpatient cases and imprecision of the estimates in the subgroup analysis due to a low number of events.

Risk of Herpes Zoster Ophthalmicus After COVID-19 Vaccination in a Large US Health Care Claims Database.

PURPOSE: Herpes zoster ophthalmicus (HZO) after COVID-19 vaccination has been reported in numerous case studies. However, no large-scale epidemiologic studies have been conducted to date. The purpose of this study was to determine whether COVID-19 vaccination is associated with an increased risk of HZO. DESIGN: Retrospective before-and-after risk interval analysis. METHODS: RESULTS: In total, 1,959,157 patients received a dose of a COVID-19 vaccine during the study period and met eligibility criteria. A total of 80 individuals without a prior history of HZO were included in the analysis because they developed HZO in the risk or control period. Patients had a mean age of 54.0 years (SD = 12.3 years). There were 45 cases of HZO in the risk interval after COVID-19 vaccination. There was not an increased risk of HZO after vaccination with BNT162b2 (IRR = 0.90, 95% CI: 0.49-1.69, P = .74), mRNA-1273 (IRR = 0.74, 95% CI: 0.36-1.54, P = .42), or Ad26.COV2.S (IRR = 0.50, 95% CI: 0.07-2.56, P = .42). CONCLUSIONS: This study found no evidence of increased risk of HZO after COVID-19 vaccination, providing reassurance for patients and providers who may be concerned about the safety profile of the COVID-19 vaccines.

Biophysical studies do not reveal direct interactions between human PF4 and Ad26.COV2.S vaccine.

BACKGROUND: COVID-19 vaccines have been widely used to control the SARS-CoV-2 pandemic. In individuals receiving replication-incompetent, adenovirus vector-based COVID-19 vaccines (eg, ChAdOx1 nCoV-19 [AstraZeneca] or Ad26.COV2.S [Johnson & Johnson/Janssen] vaccines), a very rare but serious adverse reaction has been reported and described as vaccine-induced immune thrombotic thrombocytopenia (VITT). The exact mechanism of VITT following Ad26.COV2.S vaccination is under investigation. Antibodies directed against human platelet factor 4 (PF4) are considered critical in the pathogenesis of VITT, suggesting similarities with heparin-induced thrombocytopenia. It has been postulated that components of these vaccines mimic the role of heparin by binding to PF4, triggering production of these anti-PF4 antibodies. OBJECTIVES: This study aimed to investigate the potential interaction between human PF4 and Ad26.COV2.S vaccine using several biophysical techniques. METHODS: Direct interaction of PF4 with Ad26.COV2.S vaccine was investigated using dynamic light scattering, biolayer interferometry, and surface plasmon resonance. For both biosensing methods, the Ad26.COV2.S vaccine was immobilized to the sensor surface and PF4 was used as analyte. RESULTS: No direct interactions between PF4 and Ad26.COV2.S vaccine could be detected using dynamic light scattering and biolayer interferometry. Surface plasmon resonance technology was shown to be unsuitable to investigate these types of interactions. CONCLUSION: Our findings make it very unlikely that direct binding of PF4 to Ad26.COV2.S vaccine or components thereof is driving the onset of VITT, although the occurrence of such interactions after immunization (potentially facilitated by unknown plasma or cellular factors) cannot be excluded. Further research is warranted to improve the understanding of the full mechanism of this adverse reaction.

Comparison of reporting rates of arthritis and arthralgia following AstraZeneca, Pfizer-BioNTech, Moderna, and Janssen vaccine administration against SARS-CoV-2 in 2021: analysis of European pharmacovigilance large-scale data.

This study aimed to investigate the reporting rates of arthritis and arthralgia following the administration of four vaccines against SARS-CoV-2: Pfizer-BioNTech (Tozinameran), Moderna (CX-024414), AstraZeneca (Chadox1 NCOV-19), and Janssen (AD26.COV2.S) in 2021. We used data from the EudraVigilance database, specifically analyzing spontaneous reports of suspected adverse reactions (ADRs) from the European Union (EU)/European Economic Area (EEA) region. Age-group-specific reporting rates were calculated by dividing the number of arthralgia and arthritis reports per 1,000,000 vaccine doses administered per age group. Reporting rates were compared using a rate ratio among the four vaccines, using the AstraZeneca vaccine as a comparator. The AstraZeneca vaccine was associated with the highest rate of arthralgia across all age groups. Arthritis reporting rates were significantly lower, with the AstraZeneca vaccine having the highest rates in most age groups, except the 60-69 and 80+ groups, where the Janssen and Pfizer-BioNTech vaccines demonstrated higher reporting rates, respectively. The distribution of arthritis rates did not follow the arthralgia pattern, being higher in the 50-79 age group. This study is the first spontaneous reporting system analysis of arthritis reporting rates post-SARS-CoV-2 vaccination at a European level, revealing a higher reporting of suspected musculoskeletal adverse reactions after AstraZeneca vaccination. The findings underscore the need to consider commonly reported events like arthralgia in risk-benefit assessments prior to vaccination against SARS-CoV-2. Given the high prevalence of rheumatic and musculoskeletal diseases and vaccine hesitancy in this population, our results could influence vaccine choice and acceptance.

Safety of Janssen Ad26.COV.S and Astra Zeneca AZD1222 COVID-19 Vaccines among Mobile Phone Users in Malawi: Findings from a National Mobile-Based Syndromic Surveillance Survey, July 2021 to December 2021.

The safety profiles of the Ad26.COV2.S and AZD1222 COVID-19 vaccines have not been described in the general population in Malawi. We present self-reported adverse events (AE) following the receipt of these vaccines in Malawi as part of a national syndromic surveillance survey. We conducted phone-based syndromic surveillance surveys among adults (≥18 years) with verbal consent. We used secure tablets through random digit dialing to select mobile phone numbers and collected data electronically. Survey questions included whether the respondent had received the COVID-19 vaccines, whether they had experienced any AE following vaccination, and the severity of the AE. We used multivariable analysis to identify factors associated with self-reported AE post-COVID-19 vaccination. A total of 11,924 (36.0%) out of 33,150 respondents reported receiving at least one dose of either Ad26.COV2.S or AZD1222 between July-December 2021; of those, 65.1% were female. About 49.2% of the vaccine recipients reported at least one AE, 90.6% of which were mild, and 2.6% were severe. Higher education level and concern about the safety of COVID-19 vaccines were associated with AE self-report (Adjusted Odds Ratio [AOR] 2.63 [95% CI 1.96-3.53] and 1.44, [95% CI 1.30-1.61], respectively), while male gender and older age were associated with reduced likelihood of AE self-report (AORs 0.81, [95% CI 0.75-0.88], 0.62 [95% CI 0.50-0.77], respectively). Ad26.COV2.S and AZD1222 vaccines are well-tolerated, with primarily mild and few severe AE among adults living in Malawi. Self-reporting of AE following COVID-19 vaccination is associated with gender, age, education, and concern about the safety of the vaccines. Recognizing these associations is key when designing and implementing COVID-19 vaccination communication messages to increase vaccination coverage.

Homologous Ad26.COV2.S vaccination results in reduced boosting of humoral responses in hybrid immunity, but elicits antibodies of similar magnitude regardless of prior infection.

The impact of previous SARS-CoV-2 infection on the durability of Ad26.COV2.S vaccine-elicited responses, and the effect of homologous boosting has not been well explored. We followed a cohort of healthcare workers for 6 months after receiving the Ad26.COV2.S vaccine and a further one month after they received an Ad26.COV2.S booster dose. We assessed longitudinal spike-specific antibody and T cell responses in individuals who had never had SARS-CoV-2 infection, compared to those who were infected with either the D614G or Beta variants prior to vaccination. Antibody and T cell responses elicited by the primary dose were durable against several variants of concern over the 6 month follow-up period, regardless of infection history. However, at 6 months after first vaccination, antibody binding, neutralization and ADCC were as much as 59-fold higher in individuals with hybrid immunity compared to those with no prior infection. Antibody cross-reactivity profiles of the previously infected groups were similar at 6 months, unlike at earlier time points, suggesting that the effect of immune imprinting diminishes by 6 months. Importantly, an Ad26.COV2.S booster dose increased the magnitude of the antibody response in individuals with no prior infection to similar levels as those with previous infection. The magnitude of spike T cell responses and proportion of T cell responders remained stable after homologous boosting, concomitant with a significant increase in long-lived early differentiated CD4 memory T cells. Thus, these data highlight that multiple antigen exposures, whether through infection and vaccination or vaccination alone, result in similar boosts after Ad26.COV2.S vaccination.