COVID-19 cases are rising again in the United States, and the "stratus" variant might be to blame. The big picture: A summer outbreak of COVID-19 cases isn't a shocker. But it's arriving before children head back to school,

“Stratus,” originally known as Variant XFG, is the second most prominent strain of COVID in the United States. According to the World Health Organization, the strain was first detected in Southeast Asia in January. They added the strain to its watchlist for public health risk in June.

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 estimated to be growing in PA

One COVID variant, ‘Stratus’, that has become increasingly popular in the United States during this summer and is being widely monitored by health professionals. Known officially as XFG, the variant was first detected in Southeast Asia back in January.