Americans ages 65 and older should receive an additional dose of the latest Covid vaccine this spring, scientific advisers to the Centers for Disease Control and Prevention said on Wednesday.

The spring shot would be a second dose of the most recent iteration of the Pfizer-BioNTech, Moderna or Novavax vaccines introduced in the fall. The recommendation now goes to the C.D.C. director, Dr. Mandy Cohen, who is likely to accept it.