Early evidence suggests that the highly contagious delta variant, which has prompted concern worldwide as it leads to new surges of COVID-19 across the globe, is spreading in undervaccinated pockets of the U.S.
The genomics firm Helix analyzed about 20,000 samples from COVID-19 tests across more than 700 U.S. counties. It found that cases of the variant first documented in India appear to be growing far faster in counties with lower vaccination rates than in areas that have higher rates.
The ongoing spread of the variant in pockets of low vaccine uptake are troubling because they create more opportunities for the virus to thrive and mutate. The longer the virus spreads, the more chances it has to create easier inroads into human cells, and potentially take on deadlier forms.