The new Omicron sub-variant XBB.1.5 is now 40.5% of new cases in the US. It was half that last week. In the northeast it is as much as 75% of new cases.
Not much is known about this sub-variant. It is a relative of XBB, which is immune evasive. However preliminary data on XBB shows that the bivalent vaccine produces an immune response to it. So make sure you are up to date on your vaccination with the new bivalent vaccine.
Coronavirus cases and hospitalizations are on the rise again, so consider wearing a mask in crowded settings and low ventilation environments.