Introduction
Reported adverse reactions (ARs) to Covid-19 vaccine (Cov19V) have been observed in the general population. We sought to characterize vaccine ARs amongst healthcare workers (HCW) in a large multi-site academic medical center. Our Occupational Health devised a voluntary reporting mechanism following Cov19V reactions between December 2020-June 2021. Reactions were classified as immediate if within 4 hours of Cov19V and delayed if beyond. Reaction severity, allergic or non-allergic symptoms, and subsequent recommendations were noted.
Results
464 (0.65%) reports of ARs were received among 71,281 vaccine doses. 250 (53.9%) occurred after the first dose and 149 (12.9%) after the second dose. 136 reactions were to Moderna, 298 to Pfizer, and 2 to Janssen vaccination. Most ARs were not allergic in nature (n=356, 76.7%), 57 (12.3%) were deemed allergic, while 51 (11.0%) could not be determined. The majority of ARs were immediate (66.8%) [mild (22.0%), moderate/severe (44.8%)]. 26.7% had delayed reactions [mild (8.0%), moderate (13.6%), severe (5.2%)]. 60 ARs (12.9%) required emergency room transfer. No significant differences were found between Pfizer and Moderna vaccines for increased likelihood of allergic reactions.
Conclusion
Our triage questionnaire was an efficient mechanism to capture ARs to Cov19V in an occupational setting. ARs were extremely rare and non-allergic reactions were reported more often, consistent with previous reports. Both immediate and delayed reactions are moderate to severe. Our study is limited due to the self-reported nature, the likelihood of not reporting mild or non-allergic reactions and being limited to HCW in one large institution. Follow-up studies may require more general screening.