A new Covid-19 variant, Stratus (XFG), is spreading in the US, accounting for 14 perccent of cases in just three months. It is now the third most common variant in the US.
A new Covid-19 variant, Stratus (XFG), is spreading in the US, accounting for 14 perccent of cases in just three months. It is now the third most common variant in the US.