The XFG variant, known as "Stratus," is gaining traction in the U.S., rising to 14% of cases since May. While the WHO ...

COVID-19 variant XFG accounted for 0% of U.S. cases in May. By late June it became the third-most common strain as COVID ...

The effect has been to confuse parents about whether vaccines are safe, said Northe Saunders, president of American Families ...