Scientists on alert over rising cases caused by Omicron cousin BA.2
reuters.com
reuters.com
Is this semver? Phrased as a joke, but I'm curious if anybody in the field hangs around here and knows how these bugs get their names.
So what about "BA"? To keep these sequences from getting too long, they assign aliases, and BA is the alias of B.1.1.529 (they ran out of single-letter prefixes a while ago). So BA.1 is short for B.1.1.529.1, and BA.2 is short for B.1.1.529.2, etc. (And since these are all in the Omicron family tree, they're all classed as Omicron subvariants.) Similarly, the original Delta variant was B.1.617.2, which was assigned the alias AY, so AY.1 (=B.1.617.2.1), AY.2 (=B.1.617.2.2), etc are all Delta subvariants.
The current full lineage list is available at https://cov-lineages.org/lineage_list.html. Note that they're tracking variants in far more detail than any non-virus-nerd cares about. If I'm counting right, there are 1575 non-withdrawn lineages listed, including 210 in the Delta family.