WASHINGTON (REUTERS) - Pfizer said on Monday (Nov 22) its Covid-19 vaccine provided strong long-term protection against the virus in a late-stage study conducted among adolescents aged 12 to 15.

A two-dose series of the vaccine was 100 per cent effective against Covid-19, measured seven days through over four months after the second dose, the company said.

The long-term data will support planned submissions for full regulatory approval of the vaccine in the age group in the United States and worldwide.

Pfizer and BioNTech will seek clearance for a 30 microgram dose of the vaccine for those aged 12 and above.

The vaccine was authorised for emergency use in people aged 12 to 15 by the US Food and Drug Administration in May, and granted full approval for use in people aged 16 and above in August.