Adverse Reactions of the Second Dose of the BNT162b2 mRNA COVID-19Vaccine in Healthcare Workers in Korea

Author: Yun Woo LEE ¹ ; So Yun LIM ; Ji-Hyang LEE ; Joon Seo LIM ; Miseo KIM ; Seonhee KWON ; Jiyeon JOO ; Sun Hee KWAK ; Eun Ok KIM ; Jiwon JUNG ; Hyouk-Soo KWON ; Tae-Bum KIM ; Sung-Han KIM ; Seongman BAE
Author Information

1. Department of Infectious Diseases, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
Publication Type:Brief Communication
From:Journal of Korean Medical Science 2021;36(21):e153-
CountryRepublic of Korea
Language:English
Abstract: We conducted a prospective, mobile-based survey on the self-reported adverse reactions in healthcare workers (HCWs) who received both doses of the BNT162b2 mRNA vaccine. Of the 342 HCWs who completed the two-dose vaccination, 265 (77.5%) responded to the survey at least once. Overall, the rates of adverse reactions were higher after the second dose compared with the first dose (89.1% vs. 80.1%, P = 0.006). The most common systemic reactions were muscle ache (69.1%), fatigue (65.7%), headache (48.7%), chills (44.2%), and fever (32.1%), and were notably more common after the second dose vaccine as well. We also noted a sex difference in which the frequency of adverse reactions after the second dose of the vaccine was significantly higher in females, which was not observed after the first dose. The rates of adverse reactions were lower in older age groups, and the rates and severities of the adverse reactions decreased during the 3-day period following vaccination.