This includes at least 26 cases in California, 22 cases in Florida, two cases in Colorado and one case each in Georgia and New York.
The CDC says that this does not represent the total number of cases circulating in the USA, but only those that were found by analyzing positive samples. The agency warns that its numbers, which must be updated on Tuesdays and Thursdays, may not correspond immediately to those of state and local health departments.
Although the variant appears to spread more easily, there is no evidence that it is more deadly or causes more serious illness, according to the CDC.
Experts suspect that there may be many more cases in the country and have criticized the United States for not doing more genetic sequencing of virus samples to monitor mutations.
On Sunday, a CDC official told CNN that the agency plans to more than double the number of samples it sequences over the next two weeks – with a target of 6,500 a week.
The first known US sample that carried the current version of the variant was collected on December 19 in Florida, according to the genomic database GISAID. However, collection dates are not available for all samples.
Coronaviruses mutate constantly as they circulate. What worries doctors and scientists is the possibility of the virus acquiring changes that make it less vulnerable to vaccines or treatments. So far, there is no evidence that the coronavirus can escape the effects or vaccines or treatments.