A small number of COVID-19 patients are relapsing after taking Pfizer's antiviral pill, raising questions about the drug at the center of the U.S. response effort.
Pfizer is testing three extra-small doses of its vaccine in children under 5 after two shots didn't prove quite strong enough.
The pharmaceutical company, in making its request, cited a small study that found that children given a booster had a 36-fold increase in virus-fighting antibodies.
This fourth coronavirus vaccine dose would be optional, and federal health officials aren't currently recommending it for everyone in this age group.
It would add a fourth dose to the vaccination regimen in an effort to provide maximum protection to the over-65 population.
Pfizer CEO Albert Bourla brought up the possibility of a second COVID-19 booster shot as cases of coronavirus continue to dip in some areas.
Pharmaceutical head Albert Bourla said it is preparing to submit data to the FDA that would show the effectiveness of receiving a second booster shot.
The new data comes a day after a study of New York children suggested the vaccine may not be as effective in 5- to 11-year-olds as in older kids.
The company said it will wait until it has more data on a third dose.
The nation’s 19 million children under five are the only group not yet eligible for vaccination against the coronavirus.