NB.1.8.1 — a new COVID-19 variant tied to a surge in China — now accounts for around 37% of cases in the U.S., according to variant proportion estimates from the CDC. Four notes: ...

A new COVID variant known as NB.1.8.1 is on the rise in the U.S. and beyond, landing on the radar of health officials. The variant, first identified in January 2025, is now being closely ...