(290) Myocarditis and Pericarditis in Immunocompromised Individuals Following COVID-19 mRNA Vaccination: A Living Review of Spontaneous Reports

Sunday, August 28, 2022

8:00 AM – 1:45 PM CEST

Location: Hall C

Publication Number: 1335

Presenting Author(s)

Samantha Lane
– Drug Safety Research Unit, Southampton, Hampshire, United Kingdom

Co-Author(s)

Alison Yeomans, PhD, MRes, BSc
– Research Fellow, Drug Safety Research Unit, Southampton, UK, Southampton, England, United Kingdom
Saad Shakir, MB ChB LRCP&S FRCP FFPM FISPE MRCGP
– Director, Drug Safety Research Unit, Southampton, UK, Southampton, England, United Kingdom

Background: Vaccines developed to manage the COVID-19 pandemic were the first messenger RNA (mRNA) based vaccines approved and used globally. COVID-19 mRNA vaccines are well-tolerated and effective against COVID-19 variants, although adverse events e.g., myocarditis and pericarditis occur. This novel vaccine technology stimulates the immune system differently to conventional vaccines, thus may elicit different undesired effects in immunocompromised people.

Objectives: To determine differences in age, sex, severity, time-to-onset, and vaccine dose in spontaneous reports (SR) of myocarditis/pericarditis from immunocompromised people versus the overall population, following COVID-19 mRNA vaccination.

Methods: Myocarditis/pericarditis SR following any dose of Pfizer/BioNTech or Moderna COVID-19 mRNA vaccine were obtained for immunocompromised and overall database populations, using systematic searches of SR systems from the European Union (EU; EudraVigilance), United States (US; Vaccine Adverse Event Reporting System [VAERS]) and United Kingdom (UK; data provided by Medicines and Healthcare products Regulatory Agency). Data were stratified by age, sex, time-to-onset, seriousness of reported events, and vaccine dose. Proportional reporting rates (PRR) were calculated where feasible.

Results: Myocarditis/pericarditis predominantly affected younger males in the overall population, whereas in immunocompromised people this distribution broadened and no clear trend in age/sex was observed. Time-to-onset was within 14 days of vaccination in 63.4-70.0% of immunocompromised cases and most SR followed a second vaccine dose. Myocarditis/pericarditis SR from immunocompromised people accounted for 0.84%, 1.86% and 7.1% of all myocarditis/pericarditis SR in the EU, US and UK, respectively. Reporting rates to VAERS were similar for immunocompromised and overall populations (PRR=1.36 [95% CI= 0.89-1.82]).

Conclusions: Myocarditis/pericarditis following COVID-19 mRNA vaccination is rare, and similar reporting rates were observed for immunocompromised and overall populations. Events occurred more frequently in younger males in the population overall; trends in age/sex were less clear for immunocompromised people. Continued monitoring and real-world observational studies are important to determine differences between population subgroups.