The FDA cleared a new round of Covid-19 boosters from Moderna and Pfizer/BioNTech that this time target the KP.2 variant.
The updated vaccines are expected to be available in the coming days, Moderna and Pfizer said Thursday. Both shots are now fully approved in children and adults 12 years and older, and authorized under emergency use for kids 6 months through 11 years old.
As part of an annual seasonal update to the vaccines, the FDA in June asked manufacturers to target the KP.2 variant, which was circulating at high levels at the time. KP.2 now accounts for 3.2% of total cases in the US, according to CDC data, and KP.3.1.1 is the most prevalent strain with 36.8% of cases.
Both strains are descendants of the JN.1 variant of Omicron and are part of the family of variants sometimes referred to as FLiRT.
Pfizer stressed that its KP.2-adapted vaccine generated a “substantially improved response” against other currently circulating variants in the JN.1 family, including KP.3 and LB.1, which account for 16.8% and 14.1% of current cases, respectively. The company told Endpoints News that it would have millions of doses available for shipment upon approval.
The regulatory decisions come as Covid cases surge across much of the country. On Aug. 15, 32 states and Washington, DC detected “very high” levels of Covid-19 in the wastewater.
“In the 2023-24 season, we saw more than 600,000 hospitalizations due to COVID in the US. Staying up to date with your COVID-19 vaccine remains one of the best ways for people to be protected and prevent severe illness,” Moderna CEO Stéphane Bancel said in a release.
Novavax said in June that it submitted an application for an updated version of its protein-based vaccine targeting the JN.1 lineage, which it said is active against multiple strains, including KP.2 and KP.3. A Novavax spokesperson said Thursday that it is “working productively” with the FDA as the agency completes its review.
“We expect to have authorization in time for peak vaccination season,” the spokesperson said.
“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,” Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said in a release.
Editor’s Note: This story has been updated to include comment from Novavax.