FDA approves updated Pfizer, Moderna Covid vaccines as virus surges; shots to be available within days

The Food and Drug Administration on Thursdayapproved updated Covid vaccines from Pfizer and Moderna, putting the new shots on track to reach most Americans in the coming days amid a summer surge of the virus. 

The jabs target a strain called KP.2, a descendant of the highly contagious omicron subvariant JN.1 that began circulating widely in the U.S. earlier this year. KP.2 was the dominant Covid strain in May, but now only accounts for roughly 3% of all U.S. cases as of Saturday, according to the latest Centers for Disease Control and Prevention data.

Still, Pfizer and Moderna have said their KP.2 vaccines can produce stronger immune responses against other circulating subvariants of JN.1, such as KP.3 and LB.1, than last year's round of shots targeting the omicron strain XBB.1.5 can.

"Given waning immunity of the population from previous exposure to the virus and from prior vaccination, we strongly encourage those who are eligible to consider receiving an updated COVID-19 vaccine to provide better protection against currently circulating variants," Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, said in a statement.

In June, the CDC recommended that everyone over 6 months old receive an updated Covid vaccine and flu jab this year. The new shots from Pfizer and Moderna are specifically approved for people ages 12 and older and are authorized under emergency use for children 6 months through 11 years old.  

Pfizer will begin shipping its new shot immediately and expects it to be available in pharmacies, hospitals and clinics across the U.S. "beginning in the coming days," the company said in a statement. Moderna also expects its shot to be available in a similar time frame, according to a