Allergic Reactions Including Anaphylaxis After Receipt of the First Dose of Moderna COVID-19 Vaccine — United States, December 21, 2020–January 10, 2021

During December 21, 2020–January 10, 2021, the administration of 4,041,396 first doses of Moderna COVID-19 vaccine (2,465,411 to females [61%], 1,450,966 to males [36%], and 125,019 to persons whose sex was not recorded [3%]) was reported to CDC. During the same period, reports of 1,266 (0.03%) adverse events after receipt of the first dose of Moderna COVID-19 vaccine had been submitted to VAERS. Among these, 108 case reports were identified for further review as possible cases of severe allergic reaction, including anaphylaxis, based on descriptions of signs and symptoms; 10 of these reports, all describing events in females, met the Brighton Collaboration case definition criteria for anaphylaxis

https://www.cdc.gov/mmwr/volumes/70/wr/mm7004e1.htm?s_cid=mm7004e1_w#T1_down