Surveillance of COVID-19 Vaccine Safety Among Elderly Persons Aged 65 Years and Older

Background: Monitoring safety outcomes following COVID-19 vaccination is critical for understanding vaccine safety especially when used in key populations such as elderly persons age 65 years and older who can benefit greatly from vaccination. We present new findings from a nationally representative early warning system that may expand the safety knowledge base to further public trust and inform decision making on vaccine safety by government agencies, healthcare providers, interested stakeholders, and the public. Methods: We evaluated 14 outcomes of interest following COVID-19 vaccination using the US Centers for Medicare & Medicaid Services (CMS) data covering 28 862 893 million elderly persons. The CMS data from December 11, 2020 through May 1, 2021 included 9 214 470 COVID-19 vaccinees who received a total of 16 194 576 doses. We conducted weekly sequential testing and generated rate ratios (RR) of observed outcome rates compared to historical (or expected) rates prior to COVID-19 vaccination. Findings: Four outcomes met the threshold for a statistical signal following Pfizer-BioNTech vaccination including pulmonary embolism (PE; RR=1ˑ54), acute myocardial infarction (AMI; RR=1ˑ42), disseminated intravascular coagulation (DIC; RR=1ˑ91), and immune thrombocytopenia (ITP; RR=1ˑ44). After further evaluation, only the RR for PE still met the statistical threshold for a signal; however, the RRs for AMI, DIC, and ITP no longer did. No statistical signals were identified following vaccination with either the Moderna or Janssen vaccines. Interpretation: This early warning system is the first to identify temporal associations for PE, AMI, DIC, and ITP following Pfizer-BioNTech vaccination in the elderly. Since an early warning system does not prove that the vaccines cause these outcomes, robust epidemiologic safety studies with better adjustment for confounding are underway to further evaluate these four statistical signals. FDA strongly believes the potential benefits of COVID-19 vaccination outweigh the potential risks of COVID-19 infection.Funding Information: Funding was provided by the United States Food and Drug Administration (FDA) programmatic funds in support of vaccine safety surveillance.Declaration of Interests: None of the authors have any conflicts of interests to declare.Ethics Approval Statement: This surveillance activity was conducted as part of the FDA public health surveillance mandate.