Doctors explain allergic reactions to COVID-19 vaccine; CDC releases new guidelines

MILWAUKEE (CBS 58) -- After some reports of allergic reactions to Pfizer’s COVID-19 vaccine, the CDC released new health guidelines on Saturday, Dec. 19.

Now with Moderna’s on the way, could there be cases of adverse reactions with it as well?

State health experts say there have been no cases of severe allergic reactions in Wisconsin.

Ultimately, the body wants to fight infection, so doctors say an immune response to a COVID-19 vaccine is natural.

“And it sees these spike proteins that are made by these vaccines as foreign, and so it generates the antibodies to fight those and go neutralize them," said UW Health Department of Anesthesiology Dr. William Hartman.

Results like headaches, fever, chills and muscle aches may happen.

But doctors say don’t confuse those with more serious allergic responses.

“Anaphylaxis can be anything from somebody feeling minor chest tightness to feeling more short of breath, to feeling very short of breath," Dr. Mary Beth Graham, medical director of Infection Prevention and Control at Froedtert Hospital.

The Pfizer and Moderna doses are mRNA vaccines.

The CDC says these show the body how to make proteins that create an immune response.

Graham mRNA is not a live virus, and that the body’s allergic reaction is likely caused by another part of the vaccine.

“And for many vaccine reactions that we’ve seen in the past, it’s usually the adjuvant that it’s in," she explained. "So people, even with older reactions to influenza vaccines it was a Thimerosal or it was some other agent in the vaccine preparation that caused the reaction for somebody.”

Graham added that the effectiveness of any vaccine is only as good as people are about protecting their overall health.

“Wearing our mask, social distancing, limiting gatherings, etc. I know America doesn’t want to hear that, but it’s the truth.”

If you’ve had severe reactions to ingredients in a COVID-19 vaccine the CDC says to avoid that specific vaccine.

For more CDC vaccine guidelines, click here.