Post-authorization safety surveillance of Ad.26.COV2.S vaccine: Reports to the Vaccine Adverse Event Reporting System and v-safe, February 2021-February 2022.

BACKGROUND: On 2/27/2021, FDA authorized Janssen COVID-19 Vaccine (Ad.26.COV2.S) for use in individuals 18 years of age and older. Vaccine safety was monitored using the Vaccine Adverse Event Reporting System (VAERS), a national passive surveillance system, and v-safe, a smartphone-based surveillance system. METHODS: VAERS and v-safe data from 2/27/2021 to 2/28/2022 were analyzed. Descriptive analyses included sex, age, race/ethnicity, seriousness, AEs of special interest (AESIs), and cause of death. For prespecified AESIs, reporting rates were calculated using the total number of doses of Ad26.COV2.S administered. For myopericarditis, observed-to-expected (O/E) analysis was performed based on the number verified cases, vaccine administration data, and published background rates. Proportions of v-safe participants reporting local and systemic reactions, as well as health impacts, were calculated. RESULTS: During the analytic period, 17,018,042 doses of Ad26.COV2.S were administered in the United States, and VAERS received 67,995 reports of AEs after Ad26.COV2.S vaccination. Most AEs (59,750; 87.9 %) were non-serious and were similar to those observed during clinical trials. Serious AEs included COVID-19 disease, coagulopathy (including thrombosis with thrombocytopenia syndrome; TTS), myocardial infarction, Bell's Palsy, and Guillain-Barré syndrome (GBS). Among AESIs, reporting rates per million doses of Ad26.COV2.S administered ranged from 0.06 for multisystem inflammatory syndrome in children to 263.43 for COVID-19 disease. O/E analysis revealed elevated reporting rate ratios (RRs) for myopericarditis; among adults ages 18-64 years, the RR was 3.19 (95 % CI 2.00, 4.83) within 7 days and 1.79 (95 % CI 1.26, 2.46) within 21 days of vaccination. Of 416,384 Ad26.COV2.S recipients enrolled into v-safe, 60.9 % reported local symptoms (e.g. injection site pain) and 75.9 % reported systemic symptoms (e.g., fatigue, headache). One-third of participants (141,334; 33.9 %) reported a health impact, but only 1.4 % sought medical care. CONCLUSION: Our review confirmed previously established safety risks for TTS and GBS and identified a potential safety concern for myocarditis.

Humoral immunogenicity of COVID-19 vaccines in patients with inflammatory rheumatic diseases under treatment with Rituximab: a case-control study (COVID-19VacRTX).

OBJECTIVES: Patients with inflammatory rheumatic diseases (IRDs) treated with the anti-CD20 mAb rituximab (RTX) have been identified as high-risk for severe COVID-19 outcomes. Additionally, there is increased risk due to reduced humoral immune response, induced by therapeutic B cell depletion. This study sought to quantify humoral response after vaccination against SARS-CoV-2 in patients with IRD treated with RTX. It also sought to elucidate the influence of the time frame between the last RTX dose and the first vaccination, or the status of B cell depletion on antibody titre. METHODS: In this case-control study, patients with IRDs previously treated with RTX were examined for humoral immune response after completing the first series of vaccinations with approved vaccines [BNT162b2 (Biontech/Pfizer), RNA-1273 (Moderna), AZD1222 (AstraZeneca/Oxford), Ad26.COV2.S (Janssen/Johnson & Johnson)]. Antibody levels were quantified using the Euroimmun Anti-SARS-CoV-2 QuantiVac ELISA (EI-S1-IgG-quant). Blood samples were taken just before the next infusion with RTX after the vaccination. The interval between the last RTX infusion and the first vaccination against SARS-CoV-2 and other possible factors influencing the antibody levels were evaluated. RESULTS: A total of 102 patients were included. Of these, 65 (64%) showed a negative antibody level (<24 IU (international unit)/ml) after the vaccination. The comparative univariate analysis of the antibody levels achieved a significant result (P = 0.0008) for the time between the last RTX infusion and first vaccination against SARS-CoV-2. No CD19+ peripheral B-cells could be detected in 73 of the patients (72%). CONCLUSION: The study confirms the negative impact of RTX on antibody level after vaccination against SARS-CoV-2. A clear relationship exists between the antibody titre and the interval between the last RTX infusion and the first vaccination, the number of peripheral B-cells, and immunoglobulin quantity. Improved understanding of the effect of these parameters can help guide synchronization of vaccination in relation to the RTX therapy regimen.

Vertigo and Dizziness After Coronavirus Disease-2019 Vaccination: A Nationwide Analysis.

BACKGROUND: Side effects occurring after COVID-19 vaccination can include vertigo and dizziness. Despite its high incidence, few studies to date have assessed dizziness/vertigo after vaccination. The present study investigated the incidence of dizziness/vertigo after COVID-19 vaccination in South Korea. METHODS: Adverse reactions to COVID-19 vaccination reported to the Korea Disease Control and Prevention Agency from February 26, 2021, to July 31, 2022 (week 74) were analyzed. The incidence rates of dizziness/vertigo in subjects vaccinated with 5 COVID-19 vaccines, AZD1222 (AstraZeneca), BNT162b2 (Pfizer-BioNTech), JNJ-78436735 (Janssen), mRNA-1273 (Moderna), and NVX-CoV2373 (Novavax), were determined. RESULTS: A total of 126 725 952 doses of COVID-19 vaccine were administered, with 473 755 suspected adverse reactions (374 per 100 000 vaccinations) reported. Vertigo/dizziness was reported after the administration of 68 759 doses, or 54.3 per 100 000 vaccinations, making it the third most common adverse reaction after headache and muscle pain. CONCLUSION: Dizziness/vertigo was generally a mild adverse reaction after COVID-19 vaccination, but it was the third most common adverse reaction in Korea. Studies are necessary to clarify the causal relationship between vaccination and dizziness/vertigo and to prepare subjects for this possible adverse reaction.

Changes in haemostasis and inflammatory markers after mRNA BNT162b2 and vector Ad26.CoV2.S SARS-CoV-2 vaccination.

INTRODUCTION: Reported thromboembolic events after SARS-CoV-2 vaccinations are still raising concerns, predominantly in non-scientific population. The aim of our study was to investigate the differences between haemostasis and inflammatory markers in the subjects vaccinated with mRNA BNT162b2 and vector Ad26.CoV2.S vaccine. MATERIALS AND METHODS: The study included 87 subjects vaccinated with mRNA BNT162b2 and 84 with Ad26.CoV2.S vaccine. All the laboratory parameters (TAT, F 1 + 2, IL-6, CRP, big endothelin-1, platelets, fibrinogen, D-dimers, VWF activity) were investigated for the mRNA vaccine at five (before the first dose, 7 and 14 days after the first and second vaccine dose), and three time points (before the first dose, 7 and 14 days after) for the vector vaccine, respectively. All the markers were measured by well-established laboratory methods. RESULTS: Our results have shown statistically higher CRP levels in the vector group 7 days after vaccination (P = 0.014). Furthermore, study has revealed statistically significant rise in D-dimers (P = 0.004) between tested time points in both vaccine groups but without clinical repercussions. CONCLUSION: Although statistically significant changes in haemostasis markers have been obtained, they remained clinically irrelevant. Thus, our study implicates that there is no plausible scientific evidence of a significant disruption in the coagulation and inflammatory processes after vaccination with BNT162b2 mRNA and Ad26.CoV2.S vector SARS-CoV-2 vaccines.

COVID-19 severity by vaccination status in the NCI COVID-19 and Cancer Patients Study (NCCAPS).

We investigated the association of SARS CoV-2 vaccination with COVID-19 severity in a longitudinal study of adult cancer patients with COVID-19. A total of 1610 patients who were within 14 days of an initial positive SARS CoV-2 test and had received recent anticancer treatment or had a history of stem cell transplant or CAR-T cell therapy were enrolled between May 21, 2020, and February 1, 2022. Patients were considered fully vaccinated if they were 2 weeks past their second dose of mRNA vaccine (BNT162b2 or mRNA-1273) or a single dose of adenovirus vector vaccine (Ad26.COV2.S) at the time of positive SARS CoV-2 test. We defined severe COVID-19 disease as hospitalization for COVID-19 or death within 30 days. Vaccinated patients were significantly less likely to develop severe disease compared with those who were unvaccinated (odds ratio = 0.44, 95% confidence interval = 0.28 to 0.72, P < .001). These results support COVID-19 vaccination among cancer patients receiving active immunosuppressive treatment.

Whole Blood Procoagulant Platelet Flow Cytometry Protocol for Heparin-Induced Thrombocytopenia (HIT) and Vaccine-Induced Immune Thrombotic Thrombocytopenia (VITT) Testing.

Heparin-induced thrombocytopenia (HIT) is a well-characterized, iatrogenic complication of heparin anticoagulation with significant morbidity. In contrast, vaccine-induced immune thrombotic thrombocytopenia (VITT) is a recently recognized severe prothrombotic complication of adenoviral vaccines, including the ChAdOx1 nCoV-19 (Vaxzevria, AstraZeneca) and Ad26.COV2.S (Janssen, Johnson & Johnson) vaccines against COVID-19. The diagnosis of HIT and VITT involve laboratory testing for antiplatelet antibodies by immunoassays followed by confirmation by functional assays to detect platelet-activating antibodies. Functional assays are critical to detect pathological antibodies due to the varying sensitivity and specificity of immunoassays. This chapter presents a protocol for a novel whole blood flow cytometry-based assay to detect procoagulant platelets in healthy donor blood in response to plasma from patients suspected of HIT or VITT. A method to identify suitable healthy donors for HIT and VITT testing is also described.

Multiple Electrode Aggregometry (Multiplate): Functional Assay for Vaccine-Induced (Immune) Thrombotic Thrombocytopenia (VITT).

Vaccine-induced immune thrombotic thrombocytopenia (VITT) was first described in 2021 and represents an adverse reaction to adenoviral vector COVID-19 vaccines AstraZeneca ChAdOx1 nCoV-19 (AZD1222) and Johnson & Johnson Ad26.COV2.S vaccine. VITT is a severe immune platelet activation syndrome with an incidence of 1-2 per 100,000 vaccinations. The features of VITT include thrombocytopenia and thrombosis within 4-42 days of first dose of vaccine. Affected individuals develop platelet-activating antibodies against platelet factor 4 (PF4). The International Society on Thrombosis and Haemostasis recommends both an antigen-binding assay (enzyme-linked immunosorbent assay, ELISA) and a functional platelet activation assay for the diagnostic workup of VITT. Here, the application of multiple electrode aggregometry (Multiplate) is presented as a functional assay for VITT.

Psychometric evaluation of the Symptoms of Infection with Coronavirus-19 (SIC): results from a cross-sectional study and a phase 3 clinical trial.

BACKGROUND: The Symptoms of Infection with Coronavirus-19 (SIC) is a 30-item patient-reported outcome (PRO) measure scored by body system composites to assess signs/symptoms of coronavirus disease 2019 (COVID-19). In addition to cross-sectional and longitudinal psychometric evaluations, qualitative exit interviews were conducted to support the content validity of the SIC. METHODS: In a cross-sectional study, adults diagnosed with COVID-19 in the United States completed the web-based SIC and additional PRO measures. A subset was invited to participate in phone-based exit interviews. Longitudinal psychometric properties were assessed in ENSEMBLE2, a multinational, randomized, double-blind, placebo-controlled, phase 3 trial of the Ad26.COV2.S COVID-19 vaccine. Psychometric properties evaluated included structure, scoring, reliability, construct validity, discriminating ability, responsiveness, and meaningful change thresholds of SIC items and composite scores. RESULTS: In the cross-sectional study, 152 participants completed the SIC (mean age, 51.0 ± 18.6 years) and 20 completed follow-up interviews. Fatigue (77.6%), feeling unwell (65.8%), and cough (60.5%) were symptoms most frequently reported. SIC inter-item correlations were all positive and mostly moderate (r ≥ 0.3) and statistically significant. SIC items and Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29) scores correlated as hypothesized (all r ≥ 0.32). Internal consistency reliabilities of all SIC composite scores were satisfactory (Cronbach's alpha, 0.69-0.91). SIC composite scores correlated moderately (r = 0.30-0.49) to strongly (r ≥ 0.50) with PROMIS-29 scores and Patient Global Impression of Severity (PGIS) ratings (all P < 0.01). A variety of signs/symptoms were cited in exit interviews, and participants considered the SIC straightforward, comprehensive, and easy to use. From ENSEMBLE2, 183 participants with laboratory-confirmed moderate to severe/critical COVID-19 were included (51.5 ± 14.8 years). Strong test-retest reliabilities were observed for most SIC composite scores (intraclass correlations ≥ 0.60). Statistically significant differences across PGIS severity levels were found for all but 1 composite score, supporting known-groups validity. All SIC composite scores demonstrated responsiveness based on changes in PGIS. CONCLUSIONS: The psychometric evaluations provided strong evidence for the reliability and validity of the SIC for measuring COVID-19 symptoms, supporting its use in vaccine and treatment trials. In exit interviews, participants described a broad range of signs/symptoms consistent with previous research, further supporting the content validity and format of the SIC.

Coronavirus disease 2019 (COVID-19) is a serious disease that continues to evolve globally. Researchers developed the Symptoms of Infection with Coronavirus-19 (SIC), a 30-item questionnaire designed for patients to report signs and symptoms of COVID-19. In this study, the researchers formally analyzed how well the SIC measures the patient experience with COVID-19, using survey and clinical trial data as well as telephone interviews. Adults with COVID-19 and at least 2 bothersome symptoms completed the web-based survey, and some of these individuals also participated in in-depth interviews. Participants in a clinical trial for a COVID-19 vaccine also completed the SIC measure. The SIC was compared with other commonly used questionnaires that evaluate patient experience. The most commonly reported symptoms of COVID-19 were fatigue, feeling unwell, cough, weakness, and headache. The items for individual symptoms (e.g., "cough") and combined scores for body systems (e.g., "respiratory system") performed well in statistical analyses. Participants found the SIC to be straightforward, comprehensive, and easy to use. The SIC may prove useful in the future for vaccine and treatment trials for COVID-19.

Adverse outcomes of SARS-CoV-2 infection with delta and omicron variants in vaccinated versus unvaccinated US veterans: retrospective cohort study.

OBJECTIVES: To determine the association between covid-19 vaccination types and doses with adverse outcomes of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection during the periods of delta (B.1.617.2) and omicron (B.1.1.529) variant predominance. DESIGN: Retrospective cohort. SETTING: US Veterans Affairs healthcare system. PARTICIPANTS: Adults (≥18 years) who are affiliated to Veterans Affairs with a first documented SARS-CoV-2 infection during the periods of delta (1 July-30 November 2021) or omicron (1 January-30 June 2022) variant predominance. The combined cohorts had a mean age of 59.4 (standard deviation 16.3) and 87% were male. INTERVENTIONS: Covid-19 vaccination with mRNA vaccines (BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna)) and adenovirus vector vaccine (Ad26.COV2.S (Janssen/Johnson & Johnson)). MAIN OUTCOME MEASURES: Stay in hospital, intensive care unit admission, use of ventilation, and mortality measured 30 days after a positive test result for SARS-CoV-2. RESULTS: In the delta period, 95 336 patients had infections with 47.6% having at least one vaccine dose, compared with 184 653 patients in the omicron period, with 72.6% vaccinated. After adjustment for patient demographic and clinical characteristics, in the delta period, two doses of the mRNA vaccines were associated with lower odds of hospital admission (adjusted odds ratio 0.41 (95% confidence interval 0.39 to 0.43)), intensive care unit admission (0.33 (0.31 to 0.36)), ventilation (0.27 (0.24 to 0.30)), and death (0.21 (0.19 to 0.23)), compared with no vaccination. In the omicron period, receipt of two mRNA doses were associated with lower odds of hospital admission (0.60 (0.57 to 0.63)), intensive care unit admission (0.57 (0.53 to 0.62)), ventilation (0.59 (0.51 to 0.67)), and death (0.43 (0.39 to 0.48)). Additionally, a third mRNA dose was associated with lower odds of all outcomes compared with two doses: hospital admission (0.65 (0.63 to 0.69)), intensive care unit admission (0.65 (0.59 to 0.70)), ventilation (0.70 (0.61 to 0.80)), and death (0.51 (0.46 to 0.57)). The Ad26.COV2.S vaccination was associated with better outcomes relative to no vaccination, but higher odds of hospital stay and intensive care unit admission than with two mRNA doses. BNT162b2 was generally associated with worse outcomes than mRNA-1273 (adjusted odds ratios between 0.97 and 1.42). CONCLUSIONS: In veterans with recent healthcare use and high occurrence of multimorbidity, vaccination was robustly associated with lower odds of 30 day morbidity and mortality compared with no vaccination among patients infected with covid-19. The vaccination type and number of doses had a significant association with outcomes.

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.

SARS-CoV-2 S1 Subunit Booster Vaccination Elicits Robust Humoral Immune Responses in Aged Mice.

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has raised concerns about reduced vaccine effectiveness and the increased risk of infection, and while repeated homologous booster shots are recommended for elderly and immunocompromised individuals, they cannot completely protect against breakthrough infections. In our previous study, we assessed the immunogenicity of an adenovirus-based vaccine expressing SARS-CoV-2 S1 (Ad5.S1) in mice, which induced robust humoral and cellular immune responses (E. Kim, F. J. Weisel, S. C. Balmert, M. S. Khan, et al., Eur J Immunol 51:1774-1784, 2021, https://doi.org/10.1002/eji.202149167). In this follow-up study, we found that the mice had high titers of anti-S1 antibodies 1 year after vaccination, and one booster dose of the nonadjuvanted rS1Beta (recombinant S1 protein of SARS-CoV-2 Beta [B.1.351]) subunit vaccine was effective at stimulating strong long-lived S1-specific immune responses and inducing significantly high neutralizing antibodies against Wuhan, Beta, and Delta strains, with 3.6- to 19.5-fold increases. Importantly, the booster dose also elicited cross-reactive antibodies, resulting in angiotensin-converting enzyme 2 (ACE2) binding inhibition against spikes of SARS-CoV-2, including Omicron variants, persisting for >28 weeks after booster vaccination. Interestingly, the levels of neutralizing antibodies were correlated not only with the level of S1 binding IgG but also with ACE2 inhibition. Our findings suggest that the rS1Beta subunit vaccine candidate as a booster has the potential to offer cross-neutralization against broad variants and has important implications for the vaccine control of newly emerging breakthrough SARS-CoV-2 variants in elderly individuals primed with adenovirus-based vaccines like AZD1222 and Ad26.COV2.S. IMPORTANCE Vaccines have significantly reduced the incidences of severe coronavirus disease 2019 (COVID-19) cases and deaths. However, the emergence of SARS-CoV-2 variants has raised concerns about their increased transmissibility and ability to evade neutralizing antibodies, especially among elderly individuals who are at higher risks of mortality and reductions of vaccine effectiveness. To address this, a heterologous booster vaccination strategy has been considered as a solution to protect the elderly population against breakthrough infections caused by emerging variants. This study evaluated the booster effect of an S1 subunit vaccine in aged mice that had been previously primed with adenoviral vaccines, providing valuable preclinical evidence for elderly people vaccinated with the currently approved COVID-19 vaccines. This study confirms the potential for using the S1 subunit vaccine as a booster to enhance cross-neutralizing antibodies against emerging variants of concern.

Capillary leak syndrome following COVID-19 vaccination: Data from the European pharmacovigilance database Eudravigilance.

Capillary leak syndrome (CLS) emerged as new adverse event after immunization (AEFI) associated to COVID-19 vaccination. CLS is a rare condition characterized by increased capillary permeability, resulting in hypoalbuminemia, hypotension, and edema mainly in the upper and lower limbs. Our pharmacovigilance study aims to evaluate the CLS onset following receipt of COVID-19 mRNA vaccines (mRNA-1273 and BNT162b2) compared to viral vector vaccines (Ad26.COV2-S and ChAdOx1-SARS-COV-2). We carried a cross-sectional study using all Individual Case Safety Reports (ICSRs) reporting a COVID-19 vaccine as suspected drug and CLS as AEFI, which were collected in the pharmacovigilance database EudraVigilance from January 1st, 2021, to January 14th, 2022. We applied the Reporting Odds Ratio (ROR) 95% CI for the disproportionality analysis. During our study period, CLS was described as AEFI in 84 out of 1,357,962 ICRs reporting a vaccine COVID-19 as suspected drug and collected in the EV database. Overall, the ICSR reported by CLS were mainly related to the viral vector COVID-19(ChAdOx1-SARS-COV-2 = 36; Ad26.COV2-S = 9). The mRNA COVID-19 vaccines were reported in 39 ICSRs (BNT162b2 =33; mRNA-1273 =6). Majority of ICSRs were reported by healthcare professionals (71.4%). Majority of the patients were adult (58.3%) and the female gender accounted in more than 65% of ICSRs referred both to classes vaccines. In particular, women were more represented in ICSRs referred to mRNA-1273 (83.3%) and to ChAdOx1-SARS-COV-2 (72.2%). The CLS outcome was more frequently favorable in mRNA ICSRs (33,3%) than the viral vector ones (13.3%). Among the ICSRs reporting CLS with unfavorable outcome, we found also 9 fatal cases (BNT162b2 = 1; ChAdOx1-SARS-COV-2 = 4; Ad26.COV2-S = 4). From disproportionality analysis emerged a lower CLS reporting probability after vaccination with mRNA vaccines compared to viral vector-based ones (ROR 0.5, 95% CI 0.3-0.7; p <0.001).Our findings, even if subject to the limitations of spontaneous reporting systems, suggest a small but statistically significant safety concern for CLS following receipt of COVID-19 viral vector vaccines, in particular with Ad26.COV2-S. Cytokine-release following T-cell activation could be involved in CLS occurrence, but a precise mechanism has been not yet identified. COVID-19 vaccines remain attentive as possible triggers of CLS.

Classical and Next-Generation Vaccine Platforms to SARS-CoV-2: Biotechnological Strategies and Genomic Variants.

Several coronaviruses (CoVs) have been identified as human pathogens, including the α-CoVs strains HCoV-229E and HCoV-NL63 and the ß-CoVs strains HCoV-HKU1 and HCoV-OC43. SARS-CoV, MERS-CoV, and SARS-CoV-2 are also classified as ß-coronavirus. New SARS-CoV-2 spike genomic variants are responsible for human-to-human and interspecies transmissibility, consequences of adaptations of strains from animals to humans. The receptor-binding domain (RBD) of SARS-CoV-2 binds to receptor ACE2 in humans and animal species with high affinity, suggesting there have been adaptive genomic variants. New genomic variants including the incorporation, replacement, or deletion of the amino acids at a variety of positions in the S protein have been documented and are associated with the emergence of new strains adapted to different hosts. Interactions between mutated residues and RBD have been demonstrated by structural modelling of variants including D614G, B.1.1.7, B1.351, P.1, P2; other genomic variants allow escape from antibodies generated by vaccines. Epidemiological and molecular tools are being used for real-time tracking of pathogen evolution and particularly new SARS-CoV-2 variants. COVID-19 vaccines obtained from classical and next-generation vaccine production platforms have entered clinicals trials. Biotechnology strategies of the first generation (attenuated and inactivated virus-CoronaVac, CoVaxin; BBIBP-CorV), second generation (replicating-incompetent vector vaccines-ChAdOx-1; Ad5-nCoV; Sputnik V; JNJ-78436735 vaccine-replicating-competent vector, protein subunits, virus-like particles-NVX-CoV2373 vaccine), and third generation (nucleic-acid vaccines-INO-4800 (DNA); mRNA-1273 and BNT 162b (RNA vaccines) have been used. Additionally, dendritic cells (LV-SMENP-DC) and artificial antigen-presenting (aAPC) cells modified with lentiviral vector have also been developed to inhibit viral activity. Recombinant vaccines against COVID-19 are continuously being applied, and new clinical trials have been tested by interchangeability studies of viral vaccines developed by classical and next-generation platforms.

Relative Effectiveness of Coronavirus Disease 2019 Vaccination and Booster Dose Combinations Among 18.9 Million Vaccinated Adults During the Early Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Period-United States, 1 January 2022 to 31 March 2022.

BACKGROUND: Small sample sizes have limited prior studies' ability to capture severe COVID-19 outcomes, especially among Ad26.COV2.S vaccine recipients. This study of 18.9 million adults aged ≥18 years assessed relative vaccine effectiveness (rVE) in three recipient cohorts: (1) primary Ad26.COV2.S vaccine and Ad26.COV2.S booster (2 Ad26.COV2.S), (2) primary Ad26.COV2.S vaccine and mRNA booster (Ad26.COV2.S+mRNA), (3) two doses of primary mRNA vaccine and mRNA booster (3 mRNA). METHODS: We analyzed two de-identified datasets linked using privacy-preserving record linkage (PPRL): insurance claims and retail pharmacy COVID-19 vaccination data. We assessed the presence of COVID-19 diagnosis during January 1-March 31, 2022 in: (1) any claim, (2) outpatient claim, (3) emergency department (ED) claim, (4) inpatient claim, and (5) inpatient claim with intensive care unit (ICU) admission. rVE for each outcome comparing three recipient cohorts (reference: two Ad26.COV2.S doses) was estimated from adjusted Cox proportional hazards models. RESULTS: Compared with two Ad26.COV2.S doses, Ad26.COV2.S+mRNA and three mRNA doses were more effective against all COVID-19 outcomes, including 57% (95% CI: 52-62) and 62% (95% CI: 58-65) rVE against an ED visit; 44% (95% CI: 34-52) and 54% (95% CI: 48-59) rVE against hospitalization; and 48% (95% CI: 22-66) and 66% (95% CI: 53-75) rVE against ICU admission, respectively. CONCLUSIONS: This study demonstrated that Ad26.COV2.S + mRNA doses were as good as three doses of mRNA, and better than two doses of Ad26.COV2.S. Vaccination continues to be an important preventive measure for reducing the public health impact of COVID-19.

Potential mechanisms of vaccine-induced thrombosis.

Vaccine-induced immune thrombocytopenia and thrombosis (VITT) is a rare syndrome characterized by high-titer anti-platelet factor 4 (PF4) antibodies, thrombocytopenia and arterial and venous thrombosis in unusual sites, as cerebral venous sinuses and splanchnic veins. VITT has been described to occur almost exclusively after administration of ChAdOx1 nCoV-19 and Ad26.COV2.S adenovirus vector- based COVID-19 vaccines. Clinical and laboratory features of VITT resemble those of heparin-induced thrombocytopenia (HIT). It has been hypothesized that negatively charged polyadenylated hexone proteins of the AdV vectors could act as heparin to induce the conformational changes of PF4 molecule that lead to the formation of anti-PF4/polyanion antibodies. The anti-PF4 immune response in VITT is fostered by the presence of a proinflammatory milieu, elicited by some impurities found in ChAdOx1 nCoV-19 vaccine, as well as by soluble spike protein resulting from alternative splice events. Anti-PF4 antibodies bind PF4, forming immune complexes which activate platelets, monocytes and granulocytes, resulting in the VITT's immunothrombosis. The reason why only a tiny minority of patents receiving AdV-based COVID-19 vaccines develop VITT is still unknown. It has been hypothesized that individual intrinsic factors, either acquired (i.e., pre-priming of B cells to produce anti-PF4 antibodies by previous contacts with bacteria or viruses) or inherited (i.e., differences in platelet T-cell ubiquitin ligand-2 [TULA-2] expression) can predispose a few subjects to develop VITT. A better knowledge of the mechanistic basis of VITT is essential to improve the safety and the effectiveness of future vaccines and gene therapies using adenovirus vectors.

Kidney Transplantation from a Deceased Donor with COVID-19 Ad26.COV2-S Vaccine-Induced Thrombotic Thrombocytopenia.

BACKGROUND Vaccine-induced thrombosis and thrombocytopenia is a rare immune disorder documented after adenoviral vector ChAdOx1 nCOV-19 (AstraZeneca) and Ad26.COV2-S (Janssen) vaccine administration against severe acute respiratory syndrome coronavirus 2. It is a rare adverse effect with an incidence of 1 case per 100 000 exposures. The disorder represents altered immune response with proliferation of antibodies that bind to platelet factor 4 (PF4), leading to formation of thrombi and consumptive coagulopathy. Thrombosis combined with thrombocytopenia generally occurs in the first month following vaccination and can lead to fatal outcome, even in young, previously healthy individuals. These young adults ultimately may become solid organ donors. The main concerns with vaccine-induced thrombosis and thrombocytopenia solid organ donors are anti-PF4 antibodies transmission potential, risk of early major graft thrombosis, and serious bleeding. CASE REPORT In our center, 2 kidney transplantations were performed from a single brain-dead vaccine-induced thrombosis and thrombocytopenia donor following Ad26.COV2-S COVID-19 (Janssen) vaccine in October 2021, which represents the first 2 cases of kidney transplantation from a deceased vaccine-induced thrombosis and thrombocytopenia donor after immunization with Ad26.COV2-S (Janssen) vaccine. Both recipients were closely monitored in the early post-transplantation period and after discharge from the hospital. To date, both recipients have a good functioning allograft, without any evidence of vaccine-induced thrombosis and thrombocytopenia transmission. CONCLUSIONS Our results are consistent with those of previously published cases of successful vaccine-induced thrombosis and thrombocytopenia donor solid organ transplantation. Kidney allografts transplanted from vaccine-induced thrombosis and thrombocytopenia donors can have a good overall function with favorable outcomes.

A Pilot Single-Blinded, Randomized, Controlled Trial Comparing BNT162b2 vs. JNJ-78436735 Vaccine as the Third Dose After Two Doses of BNT162b2 Vaccine in Solid Organ Transplant Recipients.

Solid Organ Transplant (SOT) recipients are at significant higher risk for COVID-19 and due to immunosuppressive medication, the immunogenicity after vaccination is suboptimal. In the previous studies, booster method showed significant benefit in this population. In the current study, we compared using a mix-and-match method vs. same vaccine as a third dose in SOT recipients. This was a patient-blinded, single center, randomized controlled trial comparing BNT162b2 vs. JNJ-78436735 vaccine as the third dose after two doses of BNT162b2 vaccine. We included adult SOT recipients with functional graft who had received two doses of BNT162b2 vaccine. Participants were randomly assigned to receive either BNT162b2 or JNJ-78436735 in one-to-one ratio. Primary outcome was SARS-CoV-2 IgG positivity at 1 month after the third dose. Sixty SOT recipients, including 36 kidney, 12 liver, 2 lung, 3 heart, and 5 combined transplants, were enrolled, and 57 recipients were analyzed per protocol. There were no statistically significant differences between the two vaccine protocols for IgG positivity (83.3% vs. 85.2% for BNT162b2 and JNJ-78436735, respectively, p = 0.85, Odds Ratio 0.95, 95% Confidence Interval 0.23-4.00). Comparison of the geometric mean titer demonstrated a higher trend with BNT162b2 (p = 0.09). In this pilot randomized controlled trial comparing mix and match method vs. uniform vaccination in SOT recipients, both vaccines were safely used. Since this was a small sample sized study, there was no statistically significant difference in immunogenicity; though, the mix and match method showed relatively lower geometric mean titer, as compared to uniform vaccine. Further studies need to be conducted to determine duration of this immunogenicity. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT05047640?term=20210641&draw=2&rank=1, identifier 20210641.

Heterologous versus homologous boosting elicits qualitatively distinct, BA.5-cross-reactive T cells in transplant recipients.

BackgroundThe SARS-CoV-2 Omicron BA.5 subvariant escapes vaccination-induced neutralizing antibodies because of mutations in the spike (S) protein. Solid organ transplant recipients (SOTRs) develop high COVID-19 morbidity and poor Omicron variant recognition after COVID-19 vaccination. T cell responses may provide a second line of defense. Therefore, understanding which vaccine regimens induce robust, conserved T cell responses is critical.MethodsWe evaluated anti-S IgG titers, subvariant pseudo-neutralization, and S-specific CD4+ and CD8+ T cell responses from SOTRs in a national, prospective, observational trial (n = 75). Participants were selected if they received 3 doses of mRNA (homologous boosting) or 2 doses of mRNA followed by Ad26.COV2.S (heterologous boosting).ResultsHomologous boosting with 3 mRNA doses induced the highest anti-S IgG titers. However, antibodies induced by both vaccine regimens demonstrated lower pseudo-neutralization against BA.5 compared with the ancestral strain. In contrast, vaccine-induced S-specific T cells maintained cross-reactivity against BA.5 compared with ancestral recognition. Homologous boosting induced higher frequencies of activated polyfunctional CD4+ T cell responses, with polyfunctional IL-21+ peripheral T follicular helper cells increased in mRNA-1273 compared with BNT162b2. IL-21+ cells correlated with antibody titers. Heterologous boosting with Ad26.COV2.S did not increase CD8+ responses compared to homologous boosting.ConclusionBoosting with the ancestral strain can induce cross-reactive T cell responses against emerging variants in SOTRs, but alternative vaccine strategies are required to induce robust CD8+ T cell responses.FundingBen-Dov Family; NIH National Institute of Allergy and Infectious Diseases (NIAID) K24AI144954, NIAID K08AI156021, NIAID K23AI157893, NIAID U01AI138897, National Institute of Diabetes and Digestive and Kidney Diseases T32DK007713, and National Cancer Institute 1U54CA260492; Johns Hopkins Vice Dean of Research Support for COVID-19 Research in Immunopathogenesis; and Emory COVID-19 research repository.

Booster with Ad26.COV2.S or Omicron-adapted vaccine enhanced immunity and efficacy against SARS-CoV-2 Omicron in macaques.

Omicron spike (S) encoding vaccines as boosters, are a potential strategy to improve COVID-19 vaccine efficacy against Omicron. Here, macaques (mostly females) previously immunized with Ad26.COV2.S, are boosted with Ad26.COV2.S, Ad26.COV2.S.529 (encoding Omicron BA.1 S) or a 1:1 combination of both vaccines. All booster vaccinations elicit a rapid antibody titers increase against WA1/2020 and Omicron S. Omicron BA.1 and BA.2 antibody responses are most effectively boosted by vaccines including Ad26.COV2.S.529. Independent of vaccine used, mostly WA1/2020-reactive or WA1/2020-Omicron BA.1 cross-reactive B cells are detected. Ad26.COV2.S.529 containing boosters provide only slightly higher protection of the lower respiratory tract against Omicron BA.1 challenge compared with Ad26.COV2.S-only booster. Antibodies and cellular immune responses are identified as complementary correlates of protection. Overall, a booster with an Omicron-spike based vaccine provide only moderately improved immune responses and protection compared with the original Wuhan-Hu-1-spike based vaccine, which still provide robust immune responses and protection against Omicron.