Bivalent COVID-19 mRNA Vaccine Provided Short Term Protection Against Thromboembolic Events in Immunocompetent Elderly Medicare Beneficiaries

Both corresponding author Amanda Payne and senior author Ruth Link-Gelles, Ph.D. from the Centers for Disease Control and Prevention (CDC) Coronavirus and Other Respiratory Viruses Division, National Center for Immunization and Respiratory Diseases and colleagues report in the latest Morbidity and Mortality Weekly Report on the vaccine effectiveness rate of the bivalent COVID-19 vaccine during the period September 2022 through March 2023. During that vaccine season, the bivalent COVID-19 mRNA vaccine was 47% effective in preventing thromboembolic events among immunocompetent persons aged 65 years or up who were COVID-19 positive, as well as 51% effective among adults aged 18 years and up with end stage renal disease (ESRD) receiving dialysis, compared with receipt of the original monovalent vaccines by themselves.

The CDC’s concern here is the fact that COVID-19 is associated with greater risk of thromboembolic events—from ischemic stroke and venous thromboembolism and myocardial infarction—and TrialSite reminds all COVID-19 vaccination may also be associated with these events but that was not the focus of this study.