The Food and Drug Administration (FDA) approved updated Covid vaccines from Pfizer and Moderna on Thursday, clearing the way for the new shots to be available to most Americans in the coming days, amid a summer surge in cases.
These vaccines are designed to target a strain called KP.2, a descendant of the highly contagious Omicron subvariant JN.1, which circulated widely in the U.S. earlier this year. Although KP.2 was the dominant strain in May, it now accounts for just around 3% of U.S. cases as of Saturday, according to the Centers for Disease Control and Prevention (CDC).
However, Pfizer and Moderna have stated that their KP.2 vaccines offer stronger immune responses against other circulating subvariants of JN.1, such as KP.3 and LB.1, compared to last year's vaccines, which targeted the Omicron strain XBB.1.5.
“Given the waning immunity from previous virus exposure and vaccinations, we strongly encourage those eligible to consider receiving an updated COVID-19 vaccine to provide better protection against currently circulating variants,” said Dr. Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, in a statement.
In June, the CDC recommended that everyone over six months old receive an updated Covid vaccine and flu shot this year. The newly approved vaccines from Pfizer and Moderna are specifically for people aged 12 and older, while they are authorized under emergency use for children between 6 months and 11 years old.
Pfizer announced it would begin shipping the new vaccine immediately, expecting it to be available in pharmacies, hospitals, and clinics across the U.S. within days. Moderna also expects its vaccine to be available within the same timeframe.
“Staying up to date with your COVID-19 vaccine remains one of the best ways to protect against severe illness,” said Moderna CEO Stéphane Bancel in a statement. “We appreciate the FDA’s timely review and encourage people to speak to their healthcare providers about receiving their updated COVID-19 vaccine along with their flu shot this fall.”
