The European Medicines Agency last week said it would rule soon on a similar application to give the booster jab, called Comirnaty, to teens aged 16 and 17 within the 27-nation bloc.

"EMA has started evaluating an application for the use of a booster dose of Comirnaty in adolescents aged 12 to 15 years," the Amsterdam-based agency said.

"An application in older adolescents aged 16 to 17 years is also ongoing," it added in a statement.

The EMA last October approved Comirnaty booster jabs for all people aged 18 and older, followed by a similar decision to back Moderna's Spikevax shortly afterward.

The EMA's head of vaccines strategy Marco Cavaleri last week said it was unlikely there would be a decision to approve two vaccines produced by French firms Valneva and Sanofi Pasteur -- both currently under rolling review -- before Easter.

But he added that vaccination -- in particular booster jabs -- "remained the best form of protection against serious illness from the Omicron variant of the virus".