New Covid Shots Recommended for Americans 6 Months and Older This Fall

All Americans ages 6 months and older should receive one of the new Covid-19 vaccines when they become available this fall, scientific advisers to the Centers for Disease Control and Prevention said on Thursday.

The recommendation comes as the nation faces a summer wave of Covid, with the number of infections rising in at least 39 states and territories.

Most Americans have acquired layers of immunity against the coronavirus from repeat infections or vaccine doses, or both. The vaccines now offer an incremental boost, remaining effective for only a few months as immunity wanes and the virus continues to evolve.

Still, across every age group, a vast majority of Americans who were hospitalized for Covid did not receive one of the shots offered last fall, according to data presented at a meeting of the C.D.C.’s Advisory Committee on Immunization Practices.

“Professionals and the public in general do not understand how much this virus has mutated,” said Carol Hayes, the committee’s liaison to the American College of Nurse-Midwives. “You need this year’s vaccine to be protected against this year’s strain of the virus.”

A vaccine by Novavax will target JN.1, the variant that prevailed for months in the winter and spring. The shots to be made by Pfizer and Moderna are aimed at KP.2, which until recently seemed poised to be the dominant variant.