An experimental vaccine for respiratory syncytial virus (RSV) was found to be 82 percent effective for infants when given to pregnant mothers, according to data published Wednesday, after a spike in cases of the virus last fall.
The vaccine that was developed by Pfizer was found to be 82 percent effective in preventing severe cases of RSV in infants when it was given to pregnant mothers in the second half of their pregnancy. The final data published in the New England Journal of Medicine on Wednesday confirmed preliminary findings by the drug company last year.
The success of the experimental vaccine comes as RSV cases saw a worrying spike in the U.S. in late 2022. Data from the Centers for Disease Control and Prevention shows that confirmed cases of the virus grew peaked at more than 20,000 confirmed cases in one week in mid-November and there were eight consecutive weeks at the end of 2022 where over 10,000 cases were reported.
RSV is a common respiratory virus that can become severe in infants and seniors. The rise in cases last year put a strain on children’s hospitals as they dealt with a surge of young patients that were suffering from more severe cases of the illness.
The study released Wednesday said that while the shot was successful in preventing severe cases of the illness, it did not reach its goal of more effectively preventing non-severe cases of the virus. It also said there were no safety concerns identified in the vaccine.
The Pfizer vaccine would be the first maternal vaccine available for the virus. The Food and Drug Administration is set to decide on its commercial use by August, according to Reuters.