Evaluation of Potential Adverse Events Following COVID-19 mRNA Vaccination Among Adults Aged 65 Years and Older: A Self-Controlled Study in the U.S

Abstract

Background Our near-real-time safety monitoring of 16 adverse events (AEs) following COVID-19 mRNA vaccination identified potential elevations in risk for six AEs following primary series and monovalent booster dose administration. The crude association with AEs does not imply causality. Accordingly, we conducted robust evaluations of the potential associations. Methods We conducted self-controlled case series studies of COVID-19 mRNA vaccines (BNT162b2 and mRNA-1273) in U.S. Medicare beneficiaries aged 65 years and older. Adjusted incidence rate ratio (IRRs) and 95% confidence intervals (CIs) were estimated following primary series doses for acute myocardial infarction (AMI), pulmonary embolism (PE), immune thrombocytopenia (ITP), disseminated intravascular coagulation (DIC); and following booster doses for AMI, PE, ITP, Bells Palsy (BP) and Myocarditis/Pericarditis (Myo/Peri). Results Among 3,360,981 individuals who received 6,388,542 primary series doses and 6,156,100 individuals with monovalent booster doses of either BNT162b2 or mRNA-1273, AE counts were: AMI (3,653 primary series, 16,042 booster), inpatient PE (2,470 primary, 5,085 booster), ITP (1,085 primary, 88 booster), DIC (254 primary), BP (3,268 booster), and Myo/Peri (1,295 booster). The IRR for inpatient PE cases following BNT162b2 primary series and booster was 1.19 (95% CI: 1.03 to 1.38) and 0.86 (95% CI: 0.78 to 0.95), respectively; and for mRNA-1273 primary series and booster, 1.15 (95% CI: 0.94 to 1.41) and 0.87 (95% CI: 0.79 to 0.96), respectively. The IRR for BP following BNT162b2 and mRNA-1273 booster was 1.17 (95% CI: 1.06 to 1.29) and 1.16 (95% CI: 1.05 to 1.29), respectively. Conclusion In these two studies of the U.S. elderly we did not find an increased risk for AMI, ITP, DIC, and Myo/Peri; the results were not consistent for PE; and there was a small elevated risk of BP after exposure to COVID-19 mRNA vaccines. These results support the favorable safety profile of COVID-19 mRNA vaccines administered in the elderly.

Risk of Adverse Events Following Monovalent Third or Booster Dose of COVID-19 mRNA Vaccination in U.S. Adults Ages 18 Years and Older

“…The PE signal was marginal and similar to inconsistent results detected in previous COVID-19 vaccine safety studies where a protective effect following third doses of both mRNA brands and a small statistically significant elevated risk following BNT162b2 primary series were observed for PE. 24 Among those with a prior COVID-19 diagnosis, nine AEs signaled. Most of these AEs have been reported to be associated with COVID-19 infection itself.…”

“…The PE signal was marginal and similar to inconsistent results detected in previous COVID-19 vaccine safety studies where a protective effect following third doses of both mRNA brands and a small statistically significant elevated risk following BNT162b2 primary series were observed for PE. 24…”

“…Myocarditis/pericarditis and anaphylaxis have been reported to be associated with the primary doses of vaccines. 3,4,8,[10][11][12][13][14][15][16][17][18][19][20][21][22]24 There is a high level of outcome misclassification (a non-case being identified as a case or vice versa) associated with the detection of BP cases and hence uncertainty with its signal as results from a medical record review (MRR) of a sample of BP cases in our other COVID-19 vaccine studies showed a low positive predictive value (PPV) (<20%, data not shown) of the claims-based diagnosis codes used to identify cases indicating that most cases resulting in the signal were not true cases. The PE signal was marginal and similar to inconsistent results detected in previous COVID-19 vaccine safety studies where a protective effect following third doses of both mRNA brands and a small statistically significant elevated risk following BNT162b2 primary series were observed for PE.…”

Risk of Neurologic or Immune-Mediated Adverse Events After COVID-19 Diagnosis in the United States

“…Given the longer time period for neurologic conditions to manifest, the ndings within this report potentially underestimated this association given the analyses' short follow-up period (6, 45,47,48). (49). We did not adjudicate outcome diagnoses using medical record review; therefore, we do not know if all identi ed outcomes are true outcomes.…”

Efetividade e eventos adversos da vacina contra influenza H1N1: Uma revisão integrativa

“…Embora a vacinação contra o vírus da influenza H1N1 seja geralmente considerada segura e bem tolerada, reações adversas podem ocorrer em uma pequena proporção de indivíduos vacinados. Estas reações podem variar em gravidade e manifestação, desde sintomas leves e transitórios, como dor no local da injeção e febre baixa, até reações mais raras, como anafilaxia (Rodrigues & de Marchi, 2020;Shi et al, 2023).…”