Omicron Xbb.1.5 Subvariant. Omicron has outperformed the earlier alpha, beta, gamma and delta coronavirus variants since. Omicron xbb.1.5 is a recombinant (or a hybrid) of two omicron sublineages that descended from another omicron subvariant called ba.2, according to experts at the.

Here is what we know so far: The european commission granted a marketing authorisation on 31 october 2023.