I wanted to summarize what is known about the new XBB.1.5 variant of SARS-CoV-2, which is starting to generate a lot of interest.
(There are no new scientific results in this thread, it simply aggregates previously reported results for those not following topic closely.)
Reason people are discussing XBB.1.5 is because it's so transmissible. Below are estimates of current Rt (measure of transmissibility) of different variants in US from @trvrb's group.
XBB.1.5 is more transmissible than other variants like BQ.1.1 that until recently dominated in US.
High transmissibility means XBB.1.5 is becoming responsible for larger fraction of COVID-19 cases.
This continues a pattern of strain replacement we've seen over last few years of SARS-CoV-2 evolution (see below).
Eg, there will always be new variants spreading, and right now it's XBB.1.5.
Bloom Lab
Skylar Hopkins