CDC: No sign of homegrown U.S. coronavirus variant, but scientists need to look harder
By Joel Achenbach, Kim Bellware and Hamza Shaban
Mutations in the novel coronavirus and the sudden appearance of the highly contagious United Kingdom variant have become a top concern of scientists and public health officials in the United States, who are vowing to improve the spotty surveillance of the pathogen as it adapts to its human host and potentially becomes a more elusive target for vaccines.
Infectious-disease experts say there is no evidence the massive winter surge that is killing thousands of people a day in the United States is linked to the U.K. variant or to a homegrown strain. But they acknowledge their battlefield awareness is limited. Some states have minimal capacity to conduct genomic sequencing that allows scientists to trace the random mutations that could give a virus variant some advantage over other strains.
The increase in the rate of new infections in the United States has been so rapid in recent weeks that scientists cannot rule out the possibility that an undetected variant is accelerating the spread.