The B.1.1.7 coronavirus variant, first identified in the U.K., is now the most common strain circulating the U.S., Rachelle Walensky, MD, director of the CDC, said during an April 7 White House news briefing.
Last week, CDC estimates found the variant accounted for at least 26 percent of all U.S. infections.
The CDC currently lists the B.1.1.7 variant as a "variant of concern," and believes it is about 50 percent more transmissible than other previously dominant coronavirus strains. The variant is also likely to have an increased disease severity based on hospitalizations and case fatality rates.
The U.S. has reported 16,275 cases of this variant as of April 6, with Florida (3,192) and Michigan (1,649) recording the highest number of B.1.1.7 cases.
After months of progress, COVID-19 cases are rising in most states, with many experts pointing to the rapid spread of variants. Ultimately, COVID-19 vaccines are effective, but the variants underscore a renewed need for caution right now.