CDC, WHO establish new threat levels for COVID-19 variants

CDC and the World Health Organization (WHO) have released three new designations to classify variants of SARS-CoV-2: “variant of interest”; “variant of concern”; and “variant of high consequence.” A variant of interest indicates it causes discrete clusters of infections, or seems to be driving a surge in cases. Such a variant also has gene modifications that suggest it might be more contagious or likely to escape immunity; CDC is currently watching three of these. A variant of concern has been proven through scientific research to be more contagious or to cause more severe disease; the CDC is tracking five of these. A variant of high consequence causes more severe disease and greater numbers of hospitalizations while defeating medical countermeasures. So far, none of the variants meet this definition. CDC says it wants to cast a wider net when designating variants of interest but would require stronger evidence before it would name a variant of concern. Going forward, final decisions on which variants are important to pay attention to will be made by CDC in consultation with the new SARS Interagency Group, comprising experts from NIH, FDA, Department of Defense, the Biomedical Advanced Research and Development Authority, and the Department of Agriculture. Beyond the new CDC/WHO designations, Public Health England is using an additional classification for “variants under investigation,” indicating they are newly identified and are the subject of ongoing studies.