Vaccine allergic reactions occur but are not common

Posted at 4:28 PM, Dec 23, 2020
and last updated 2020-12-24 10:50:23-05

With the rollout of the new COVID-19 vaccines, reports of allergic reactions have caused alarm.

Two Idahoans, one up north and one in the Treasure Valley, suffered allergic reactions after receiving their Pfizer COVID-19 vaccine shots.

According to the Idaho Department of Health and Welfare, both have had allergic reactions to injectable medication before.

"Allergic reactions to vaccines do occur, they are not frequent, but about 1 in a million do occur," Allergist Immunologist Jeremy Waldram said.

The common side effect most are having to the COVID-19 vaccines is an expected sore arm, but the vaccine caused an allergic reaction for just a handful.

"With any vaccine or really any medication, there can be an allergic reaction to those things," Waldram said.

It isn't exactly known yet, just what could be the source of the reaction.

"So far, all of those patients had a history, and we haven't really seen that happen so far in anyone who didn't have that history," Saint Alphonsus Nampa Pharmacy Manager Lisa Thoroughman said.

Each vaccine carries various components, and it could be any one of them, causing a reaction. Medical experts say one suspicion that could be the culprit is a stabilizing molecule found in the Pfizer vaccine named "polyethylene glycol."

The state recommends anyone with a history of anaphylaxis to any vaccine should wait on getting it until more is known.

Safety precautions include waiting around for 15 minutes or so minutes after getting the shot.

"If somebody was to receive the vaccine and go home and have a reaction, the first thing to do would be to take some oral Benadryl, and that is your classic treatment for any type of an allergic reaction," Thoroughman said.

Again, these allergic reactions are rare and do not happen to everybody. Only a handful of people have had them and they have been known to have prior reactions to injectable medicine before.

"Vaccination can cause allergic reactions. They are not common, but they do occur. This is not entirely unexpected, but there are precautions in place, and I certainly don't think the fear of an allergic reaction should prevent people from getting vaccinated. Still, they should follow the precautions that have been put into place," Waldram said.