June 13 (Reuters) - GSK said on Friday the

European Medicines Agency had accepted the drugmaker's

application to expand the use of its respiratory syncytial virus

(RSV) vaccine, Arexvy, to adults aged 18 and above.

An expanded approval will help GSK better compete with

rivals such as Merck's ( MRK ) mRESVIA and Pfizer's ( PFE )

Abrysvo after U.S. regulators late Thursday approved the use of

mRESVIA in adults aged 18 to 59 years at increased risk for

disease.

RSV is a common respiratory virus that causes seasonal

infections such as the flu, but is a leading cause of pneumonia

and death in infants and older adults.

The approval could also help GSK revive falling vaccine

sales. In the first quarter, Arexvy brought in just 0.1 billion

pounds ($135.4 million) in sales, down 57%.

GSK had projected Arexvy to be a blockbuster product,

estimating peak annual sales of 3 billion pounds, but sales have

missed market expectations for several quarters.

Arexvy is currently approved in the European Union (EU) for

adults aged 60 and above, and for preventing RSV-related disease

in at-risk adults aged 50 to 59.

A decision by the EU's health regulator on the expanded use

of the vaccine is expected in the first half of 2026, the

British drugmaker said.

($1 = 0.7387 pounds)