Immediate-Type Systemic Hypersensitivity Reactions After the Inactivated SARS-CoV-2 Vaccine in Healthcare Workers

Abstract

The vaccines developed for Coronavirus disease 2019 (COVID-19) not only brought hope to the struggle against the pandemic but also raised questions about hypersensitivity reactions that might occur. Although some studies regarding these concerns with mRNA COVID-19 vaccines have been published, these data on inactivated Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccine are not available. The objective of this study was to determine the safety of the inactivated SARS-CoV-2 vaccine manufactured by Sinovac by evaluating the reported systemic immediate hypersensitivity reactions (IHRs) after the administration of the vaccine to healthcare workers (HCWs). This was a retrospective analysis of inactivated SARS-CoV-2 vaccine recipients in all HCWs vaccinated at our center. Relevant data of all patients who received the vaccine were collected from the electronic medical records available at our center’s database. A statistical analysis of subjects who reported acute adverse reactions was conducted. Of the 3354 HCWs vaccinated with the first dose (female 59.9%, pre-existing allergic disorder 2.4%), four acute adverse reactions (0.12%) met the definition of a systemic IHRs were reported, and only one was confirmed to be anaphylaxis. One out of these four cases received her second dose through graded administration. For the second dose, no systemic reaction was reported in our study population. Inactivated SARS-CoV-2 vaccine appears to be well tolerated in HCWs without any pre-existing allergic disorders.