The Vaccines and Related Biological Products advisory committee (VRBPAC) voted 21 to zero in favour of the monovalent XBB-lineage vaccines, and generally agreed that vaccines targeting the XBB.1.5 subvariant would be preferred.
XBB.1.5, which is another descendant of the Omicron variant, has previously been described as the ‘most transmissible’ subvariant because the mutations it contains allow it to adhere to cells and replicate easily.
The variant accounted for nearly 40% of all COVID-19 cases in the US at the beginning June, according to data from the Centers for Disease Control and Prevention (CDC), with the related XBB.1.16 and XBB.2.3 variants on the rise.
