The U.S. drug regulator on Monday expanded the use of a third shot of Pfizer Inc.'s coronavirus vaccine to children aged 12 to 15 and also shortened the wait time for a booster shot from six to five months.
The amended emergency-use authorization means that Pfizer's single booster dose is now approved for individuals 12 years of age and older in the United States, where the highly transmissible Omicron variant of the virus is spreading rapidly.
The latest decision came after the U.S. Food and Drug Administration reviewed data from Israel, including safety data from more than 6,300 individuals 12 through 15 years of age who received a booster dose at least five months following completion of the primary two-dose vaccination series.
"The data shows there are no new safety concerns following a booster in this population," the FDA said in a press release.
While cases of myocarditis -- an inflammation of the heart muscle -- have been reported especially in male adolescents and young adults after the inoculation of mRNA type vaccines such as Pfizer's, an FDA official said expectations are that side effects from a third dose would be "extremely rare."
Cases of myocarditis that occur with the mRNA vaccines have been relatively mild and have generally led to hospitalization of one day, another official said.
The FDA, meanwhile, noted that data from multiple laboratories indicate that a booster dose of the Pfizer vaccine "greatly improves" an individual's antibody response to counter the Omicron variant.
"Authorizing booster vaccination to take place at five months rather than six months may therefore provide better protection sooner for individuals" against Omicron, it said.
As for other vaccines, the FDA has left the booster interval unchanged at six months for Moderna Inc.'s two-dose mRNA vaccine and two months for Johnson & Johnson's single-dose vaccine. Currently, those aged 18 years or older are eligible for the two vaccines.
Related coverage:
Pentagon chief Austin tests positive for COVID-19, symptoms mild
European nations, U.S. report record COVID-19 cases as Omicron spreads
COVID-19 vaccination for children aged 5-11 under way in U.S
