A new COVID variant is spreading in the US: What are the symptoms?

A new COVID-19 variant that was unheard of just months ago is now projected to be the second-most common strain in the U.S.

Variant NB.1.8.1 was first detected in China in January but accounted for about 0% of cases in the U.S. until May. By early June, it was estimated to account for up to 37%, according to the U.S. Centers for Disease Control (CDC).

The World Health Organization (WHO) evaluated the additional public health risk posed by the variant as "low at the global level in a May report, in which it also advised that currently approved COVID-19 vaccines are "expected to remain effective to this variant against symptomatic and severe disease."

Here's what we know about NB.1.8.1.

'Razor blade throat': What to know about COVID-19 variant NB.1.8.1