UPDATE 1-U.S. FDA grants priority review to Pfizer's RSV vaccine

(Adds review date and background)

Dec 7 (Reuters) - Pfizer Inc said on Wednesday the U.S. Food and Drug Administration will review its respiratory syncytial virus (RSV) vaccine candidate on priority.

The drugmaker is seeking approval for use of the vaccine, RSVpreF, in adults aged 60 years and older and the agency is set to make its decision by May 2023. It could become the first approved RSV vaccine in the U.S. for older adults who are at risk of the lung disease.

Pfizer's application to the FDA is supported by data from a late-stage study in which the vaccine was found safe and effective.

The vaccine was 85.7% effective among participants with three or more symptoms, and 66.7% for two or more symptoms, according to an interim analysis carried out by an external data monitoring panel.

There are no U.S. approved vaccines for RSV, a common virus that typically causes mild cold-like symptoms but can be fatal for young kids and older adults. RSV is estimated to cause about 14,000 annual deaths among older adults in the United States.

(Reporting by Bhanvi Satija and Khushi Mandowara in Bengaluru; Editing by Krishna Chandra Eluri)