Pfizer is asking the US government to allow use of its COVID-19 vaccine in children aged five to 11.
If regulators agree, shots could begin within a matter of weeks.
Pfizer already had announced that a lower dose of its vaccine worked and appeared safe in a study of the youngsters.
Pfizer and its German partner BioNTech on Thursday officially filed its application with the Food and Drug Administration.
FDA's advisers are scheduled to debate the evidence on October 26.
Until now, the vaccine was available only to those as young as 12.
Children currently make up about 27 per cent of all US coronavirus cases and an increasing percentage of hospitalisations, according to the American Academy of Pediatrics.
That reflects the high contagiousness of the Delta variant among unvaccinated people.
While kids are less susceptible to severe COVID-19, they can spread the virus to others, including vulnerable populations that are more at risk of severe illness.
Australian Associated Press
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