The US Food and Drug Administration (FDA) yesterday announced that it has changed the date of its upcoming Vaccines and Related Biological Products Advisory Committee (VRBPAC) from May 16 to June 5, during which the group will discuss and make recommendations on the strain or strains to include in 2024-25 COVID vaccines.

In an X post, the FDA said the new date will allow more time to obtain surveillance data and other information so that the group has the most up-to-date information for making its recommendations. The agency added that it doesn't expect that the date change will hamper vaccine availability for the fall.
Current vaccines target the XBB.1.5 variant, but JN.1 has become the dominant strain. The World Health Organization (WHO) COVID vaccine advisory group recently met and recommended a switch to a monovalent (single-strain) vaccine containing the JN.1 antigen.
However, scientists have been tracking a steady rise in JN.1 offshoots that have two added spike mutations, nicknamed the FLiRT (F for L at position 456 and R for T at position 346), which may give them more immune-evasive properties. In the United States, for example, the proportion of KP.2, which has the FLiRT mutations, recently topped the parent JN.1 strain.