BNT162b2 mRNA COVID-19 vaccine adverse reactions needing medical support: a vaccine center experience

ABSTRACT

Objective@#The coronavirus disease 2019 (COVID-19) pandemic has not yet been controlled and herd immunity through vaccination against COVID-19 has been considered the best option to prevent the spread of COVID-19 worldwide. We encountered several patients in our emergency department presenting with adverse reactions after COVID-19 vaccinations. Hence, we investigated the clinical characteristics of patients with adverse reactions after vaccination. @*Methods@#In South Korea, 10,510 doses of the BNT162b2 mRNA COVID-19 vaccine was administered to 5,304 medical staff. To investigate adverse reactions, we reviewed the case report forms from the vaccination centers and the medical charts from the date of first dose administration until two weeks after the last planned second dose. @*Results@#A total of 187 cases, out of the 10,510, experienced adverse reactions and these were more common in females. Dizziness (44.4%), nausea and vomiting (28.3%), and fever (24.1%) were the most reported adverse reactions. Immediate adverse reactions included dizziness, nausea, and vomiting, palpitation, sensory changes, and delayed adverse reactions included fever, myalgia, headache, nausea, and vomiting. The delayed reactions of fever and myalgia were significantly more common after the second, rather than after the first dose (P<0.01 and P=0.03, respectively). One case of anaphylaxis was reported. All adverse reactions improved after conservative care. @*Conclusion@#Our findings show diverse adverse reactions to the BNT162b2 mRNA COVID-19 vaccine, but none of them required hospitalization. However, since this vaccine has been manufactured using a newly developed technique, more research focused on the clinical significance of the adverse reactions is necessary.