Pfizer-BioNTech COVID-19 (left) and Modern COVID-19 (right) vaccines.
Matic Zorman | Getty Images
The National Institutes of Health said Wednesday they began investigating why some people suffered severe allergic reactions shortly after receiving the Pfizer-BioNTech and Moderna Covid-19 vaccines.
“The public is understandably concerned about the reports of rare, severe 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 trial will help doctors advise people who are very allergic or have a mast cell disorder about the risks and benefits of receiving these two vaccines. For most people, the benefits of vaccination are COVID-19, however, far outweighs the risks., “He said.
Medical experts say allergic reactions to vaccines are rare but can sometimes occur. Most of the rare, severe 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 four hours of vaccination, and may include symptoms such as hives, swelling, and wheezing, according to the Centers for Disease Control & Prevention.
The NIH study will enroll 3,400 adults ages 18 to 69 at up to 35 academic centers for allergy research nationwide, the agency said. Participants will be divided into groups and will be randomly assigned to receive 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 allergy, asthma and airway biology branch, told CNBC in December that U.S. agency researchers had become interested in the rare phenomenon after reports that some people had reactions to Pfizer’s vaccine that qualifies as anaphylaxis, a severe and potentially life-threatening allergic reaction.
The CDC has asked healthcare providers to monitor patients for 15 minutes after vaccination and 30 minutes for those with a history of allergic reactions.
If someone has a severe allergic reaction after the first dose of a Covid-19 vaccine, the CDC recommends that they do not receive the second dose of the vaccine, even if the allergic reaction was not severe enough to require emergency care. not.