Pfizer on Monday said a large-scale trial has shown that its Covid-19 vaccine is safe and effective for those aged 5 to 11, which could pave the way forward for children in this age group to be inoculated within months.
The company and its partner, BioNTech, added that they will seek US authorisation for this age group soon.
Janet Woodcock, acting commissioner of the US Food and Drug Administration, said that once the agency receives the application, its process for determining if the vaccine is safe and effective for children in the younger age group includes verifying the manufacturing processes for lower concentrations of the shot and a study of its safety.
"We'll look at the clinical data and make sure that children responded to the vaccine the way we would expect," Ms Woodcock said.
Top US health officials believe a decision could be made within three weeks of the companies submitting a request for authorisation, Reuters reported.
Children aged 5 to 11 will receive two shots of a 10-microgram dose of the vaccine, a third of the dose size given to those aged 12 and older.
Unlike the larger clinical trial that the drugmakers previously conducted in adults, the 2,268-participant pediatric trial was not primarily designed to measure the vaccine's efficacy by comparing the number of Covid-19 cases in vaccine recipients to those who received a placebo.
Instead, it compares the amount of neutralising antibodies induced by the vaccine in children to the response of older recipients in the adult trial.
Pressure to immunise children has mounted in the US with the beginning of the school year, and the highly transmissible Delta variant has led to a surge in cases.
A recent report from the American Academy of Pediatrics noted that children accounted for 28 per cent of US Covid-19 cases. There is no indication, however, that the Delta variant is more dangerous for children.
The Pfizer vaccine is one of three administered in the US and the only one to have received full FDA approval.
Pfizer said its vaccine was 95 per cent effective in the adult clinical trial, but argued its strength wanes after several months. Last week, the FDA advisory panel rejected Pfizer's proposal for a booster shot for the general US population, but approved one for older and high-risk Americans.
Reuters contributed to this report