A panel of expert advisers to the U.S. Food and Drug Administration on Thursday unanimously voted to recommend booster shots of Moderna Inc.'s COVID-19 vaccine for Americans age 65 and older and those at high risk of severe illness or occupational exposure to the virus.

If the FDA signs off on Moderna's booster, the U.S. Centers for Disease Control and Prevention will make specific recommendations on who should get the shots. CDC advisers are scheduled to meet next week.

The FDA's Vaccines and Related Biological Products Advisory Committee met on Thursday to consider the additional dose of the Moderna vaccine and will weigh whether to make a similar recommendation for Johnson & Johnson's vaccine on Friday. The vote to back Moderna's booster was 19-0.