PFIZER INC has formally asked the UK medical regulator for permission to use its COVID-19 vaccine for 12-to 15-year olds in Britain, the Telegraph reported on Tuesday.

"We can confirm that the companies have submitted a request to the MHRA to expand the use of the Pfizer-BioNTech COVID vaccine in the UK to adolescents, the report said, citing a Pfizer spokesman.

Pfizer and the MHRA did not immediately response to Reuters requests for comment.

The move comes as U.S. regulators on Monday authorized Pfizer and BioNTech's COVID-19 vaccine for use in children as young as 12, widening the country's inoculation program as vaccination rates have slowed significantly.