Pfizer-BioNTech COVID-19 (left) and Moderna COVID-19 (right) vaccines.
Matic Zorman | Getty Images
The National Institutes of Health said Wednesday it has begun to investigate why some people have experienced severe allergic reactions shortly after receiving the Pfizer-BioNTech and Moderna Covid-19 vaccines.
“The public is understandably concerned about reports of rare serious allergic reactions to the Moderna and Pfizer-BioNTech COVID-19 vaccines,” said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which is part of the NIH. , said in a statement.
“The information gathered during this study will help doctors to advise people who are highly allergic or have mast cell disease about the risks and benefits of receiving these two vaccines. For most people, the benefits of COVID-19 outweigh. However, vaccination far outweighs the risks, ”he said.
Medical experts say allergic reactions from vaccines are rare, but can sometimes occur. Most of the rare, serious allergic reactions to the vaccines have occurred in people with a history of allergies, public health officials said. An immediate allergic reaction usually occurs within 4 hours of vaccination and can include symptoms such as hives, swelling, and wheezing, according to the Centers for Disease Control and Prevention.
The NIH study will enroll 3,400 adults ages 18 to 69 at up to 35 nationwide allergy research centers, the agency said. Participants are divided into groups and randomly assigned to receive either the Pfizer-BioNTech vaccine, the Moderna vaccine, a placebo followed by the Pfizer-BioNTech vaccine, or a placebo followed by the Moderna vaccine.
Alkis Togias, head of the NIAID’s division of allergy, asthma and respiratory biology, told CNBC in December that researchers at the US agency became interested in the rare phenomenon after reports that a few people had reactions to Pfizer’s vaccine that qualified as anaphylaxis. a severe and potentially life-threatening allergic reaction.
The CDC has asked health care providers to monitor patients 15 minutes after vaccination and 30 minutes for those with a history of allergic reactions.
If someone has a serious allergic reaction after receiving the first dose of a Covid-19 vaccine, the CDC recommends not getting the second dose of that vaccine, even if the allergic reaction was not severe enough to require emergency care. require.