FDA asks COVID vaccine makers to target KP.2 strain

The U.S. health regulator recently changed its strain recommendation for the 2024-25 COVID-19 vaccines, as it asked manufacturers to update the new shots to target the KP.2 variant, if feasible, instead of the JN.1 lineage it sought to target earlier.

The Food and Drug Administration’s change in recommendation, comes even as Moderna (MRNA.O) and Novavax (NVAX.O) — the makers of two of the three COVID vaccines, submitted their applications to the agency for updating the fall 2024 season shots with the JN.1 strain.

Novavax had said its manufacturing is underway for a JN.1 vaccine and it cannot have a shot this fall for another strain.

The company applied for authorisation last week and said its shot showed broad cross-neutralising antibodies against multiple variants, including KP.2 and KP.3. It said it can be ready with its JN.1 shot by mid-July.

Novavax was not immediately available for comment on the FDA’s preference for a KP.2 shot.

The FDA’s new advisory differs from recommendations of its own advisers and the European regulator and World Health Organisation (WHO), all of which sought targeting the JN.1 strain with the updated vaccines.

JN.1 was the dominant strain in the U.S. earlier this year. While it is no longer as prevalent, it is estimated to account for 3.1 per cent of cases over a two-week period ended June 8, the Centers for Disease Control and Prevention data showed.

The KP.2 variant was estimated to account for about 22.5 per cent of cases, with KP.3 now becoming dominant at 25 per cent.

Pfizer on June 14, 2024, said it was having discussions with regulators globally, including the FDA, to assess the composition of future COVID vaccine formulations. Moderna said it would be ready with the updated shot in time for the fall vaccination campaign, regardless of the final decision on the strain.

Shares of Novavax, Moderna and BioNTech each closed more than 3.5 per cent down in the U.S.