Vaccine makers should consider targeting one of the currently dominant JN.1 variants and JN.1-derived subvariants such as KP.2 as they develop COVID-19 shots for the 2024-2025 campaign, the U.S. Food and Drug Administration's staff said on Monday.
The FDA reviewers said since the difference between JN.1 and newer subvariants such as KP.2 subvariants is not much, it is possible that vaccines developed against JN.1 may adequately protect against KP.2.
But, the reviewers added that further evolution of the virus could take it away from JN.1, so vaccine makers may need to consider updating their vaccine to the currently predominant variant.
The comments were made in documents posted ahead of Wednesday's meeting of a panel of the health regulator's independent experts, who are expected to make recommendations on which strain an updated COVID booster should target.
The U.S. Centers for Disease Control and Prevention (CDC) estimated COVID subvariant KP.2 to account for about 28.5% of cases in the United States, over a two week period ending on May 25.