A new COVID-19 variant is climbing the ranks in the United States, becoming the third-most common strain of the summer. Variant XFG, colloquially known as "Stratus," was first detected in Southeast ...

A new COVID-19 variant sweeping through China has yet to make a sizable footprint in the U.S., the Centers for Disease Control and Prevention (CDC) says. In January, a new COVID-19 variant known as NB ...