July 26 (UPI) -- Many people who had allergic reactions to their first dose of the Moderna or Pfizer-BioNTech coronavirus vaccine tolerated a second dose without serious complications, according to a study published Monday in JAMA Internal Medicine.
The multi-hospital analysis suggests people who had a reaction after their first vaccine dose shouldn't let it prevent them from getting the second dose, researchers said.
As many as 2% of people who have received mRNA COVID-19 vaccinations have had allergic reactions to the first dose. Researchers examined whether those same people could get a second dose without having another reaction.
The researchers looked at medical records for 189 patients who had allergic reactions to the first dose, 32 of whom experienced a severe allergic reaction. A total of 159 patients received a second dose.
Thirty-two patients reported immediate reactions after their second dose that were self-limited, mild or resolved with antihistamines alone, researchers said.
"All patients who received a second dose safely completed their vaccination series and could use mRNA COVID-19 vaccines in the future when indicated," researchers wrote in the study.
"Second dose tolerance following reactions to the first dose argues that either many of these initial reactions are not all truly allergic reactions," or they may be caused by something that can "typically be abated with premedications," they wrote.
The U.S. Centers for Disease Control and Prevention recommended that individuals with an immediate allergic reaction to the first dose of the Pfizer-BioNTech or Moderna mRNA COVID-19 vaccines could receive a Johnson & Johnson single dose vaccine subsequently.
Previous studies have found that skin problems that developed after the first vaccines go away quickly, with another study looking at over 40,000 employees in the Boston hospital system and finding that severe allergic reactions to the vaccines were rare and resolve quickly.
In April, a vaccination site in Colorado shut down after two patients experienced anaphylaxis. Despite those cases, an incident commander reassured residents that the vaccinations would continue.