US firm Moderna said Tuesday its Covid-19 vaccine strongly protects children as young as 12.
But earlier this month, the U.S. and Canada authorised another vaccine - the shot made by Pfizer and BioNTech - to be used starting at age 12.
Moderna aims to be next in line, saying it will submit its teen data to the U.S. Food and Drug Administration and other global regulators early next month.
The company studied more than 3,700 12- to 17-year-olds.
With global vaccine supplies still tight, much of the world is struggling to vaccinate adults in the quest to end the pandemic.