Important note: This article is intended for those who understand vaccines as critical to maintaining their health and that of their families. It is NOT intended for those who are anti-vaccine and as such is NOT intended to foster a discussion on the merits of vaccines in this forum. It is also NOT intended to foster a discussion of the lethality of COVID-19 or the need for civic action to limit the spread of the disease.
The Centers for Disease Control (CDC) issued an update regarding the COVID-19 vaccine made by Moderna which was granted Emergency Use Authorization by the US Food and Drug Administration on December 19, 2020. The Moderna vaccine was the second to receive authorization after Pfizer’s candidate.
During the period December 21, 2020–January 10, 2021, monitoring by the Vaccine Adverse Event Reporting System (VAERS) reported 10 cases of anaphylaxis following administration of 4,041,396 first doses of Moderna COVID-19 vaccine. That translates to 2.5 cases per million doses administered or roughly 1 in 400,000. In nine of those cases, onset occurred within 15 minutes of vaccination. No deaths were reported.
A total of 1,266 (0.03%) adverse events after receipt of Moderna COVID-19 vaccine were submitted to VAERS. Among these, 108 case reports were identified for further review as possible cases of a severe allergic reaction including anaphylaxis.
Anaphylaxis is a life-threatening allergic reaction that occurs rarely after vaccination, with onset typically within minutes to hours. Among these case reports, 10 cases were determined to be anaphylaxis, including nine in persons with a documented history of allergies or allergic reactions, five of whom had a previous history of anaphylaxis.
Among eight persons with follow-up information available, all had recovered or been discharged home. Among the remaining case reports that were determined not to be anaphylaxis, 47 were assessed to be nonanaphylaxis allergic reactions, and 47 were considered nonallergic adverse events.
Despite anaphylaxis being extremely rare after receiving either the Moderna or Pfizer vaccine, you may want to take extra precautions when scheduling your inoculation especially if you have a prior history of severe reactions to other vaccines.
If you are concerned that you are at high risk for anaphylaxis, we suggest you refer to the article Is Your Covid Vaccine Venue Prepared to Handle Rare, Life-Threatening Reactions? which provides important guidelines for selecting an appropriate venue to receive the vaccine.