This Wednesday, March 31, 2021, file photo shows empty vials of Johnson & Johnson’s one-dose COVID-19 vaccine at a mobile vaccination site in Uniondale, N.Y. On Thursday, Oct. 21, 2021, advisers to the Centers for Disease Control and Prevention are slated to discuss who should get extra doses of the Moderna or Johnson & Johnson vaccines — and the bigger question of getting a different brand for the booster than people’s original vaccination. (AP Photo/Mary Altaffer)