The XFG “Stratus” COVID-19 variant, now the third most common in the US, is surging in 12 states with high positivity rates. Known for symptoms like “razor blade throat”, it spreads quickly but remains covered by current vaccines.

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

For the week ending Aug. 2, 6.4% of COVID-19 tests came back positive in Wisconsin, state Department of Health Services data shows.