(299) Monitoring of Adverse Events Following COVID-19 Vaccines in Department of Veterans Affairs

Publication Number: 1344

Background: In December 2020, the US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for use of Pfizer-BioNTech and Moderna COVID 19, 2-dose series of mRNA vaccines for the prevention of COVID-19 for individuals >= 16 years old. In February 2021, the FDA also issued an EUA for a single dose Janssen vaccine for individuals >= 18 years old. Safety and potential risks associated with COVID-19 vaccines were largely unknown. The Department of Veterans Affairs (VA) tracked the administration of COVID-19 vaccines and potential adverse events of special interest (AESIs) in Veteran patients.

Objectives: The objective of this rapid cycle analysis (RCA) of COVID-19 was to track vaccine administrations and monitor pre-specified AESIs following COVID-19 vaccines in a near-real time setting for all three COVID-19 vaccines.

Methods: Individuals who received COVID-19 vaccines were identified in Corporate Data Warehouse (CDW) which includes vaccines given in the VA and outside of VA using the CPT codes and CVX codes from December 14, 2020 to February 6, 2022. Pre-specified AESIs include anaphylaxis, Guillain-Barre syndrome (GBS), myocarditis/pericarditis, and others and were identified using ICD-10 codes. Patients who received any vaccines from October 2015 to February 2020 were identified and used to estimate background rates for AESIs. The Poisson-based maximized sequential probability ratio test (MaxSPRT) was applied. RCA was conducted weekly for dose 1, dose 2, and booster dose separately.

Results: Approximately, 4.07 million Moderna (2.10M dose 1 and 1.97M dose 2) and 3.69 million Pfizer (1.90M dose 1 and 1.79M dose 2), and 322 thousand Janssen vaccines were administered. In addition, about 1.62 million mRNA booster doses were administered. Among individuals who received doses 1 or 2 of mRNA vaccines, about 60% were aged 65 years or older and 88% were male. Sixty-five percent were White and 18% were Black. Individuals receiving Janssen were younger with more females. Individuals receiving booster doses were older compared to doses 1 and 2. The RCA revealed a signal for anaphylaxis but no signals for other AESIs. The observed to expected risk ratio for myocarditis/pericarditis following booster dose was larger compared with those following doses 1 and 2.

Conclusions: VA used weekly data to rapidly detect a potential signal for pre-specified AESIs following administration of COVID-19 vaccines. To date, no signals were observed for any of the pre-specified AESIs except for anaphylaxis. The observed to expected risk ratio for myocarditis/pericarditis after early booster dose data appeared higher than that of dose 1 and dose 2 but further monitoring is needed.