By Gary Evans, Medical Writer

A highly transmissible variant of the SARS-CoV-2 virus originally from the United Kingdom (U.K.) is emerging rapidly in the United States, with more than 50 cases detected in eight states as this report was filed.

The mutated strains do not appear more virulent, but the enhanced transmission narrows the margin of error for breaks in personal protective equipment and other exposures in the community and healthcare settings.

The Centers for Disease Control and Prevention (CDC) held a recent press conference to update the rapidly evolving situation.

“Health officials in the United Kingdom and South Africa recently reported two new variants of SARS CoV-2 the virus,” said Henry Walke, MD, incident manager for the CDC’s COVID-19 response. “Both appear to infect people more easily. It is important to know that at this time there is no evidence that either of these variants causes more severe disease or increases the risk of death.”

The B117 U.K. variant has undergone multiple changes, including “a mutation in the receptor binding domain (RBD) of the spike protein,” the CDC reports. This mutation apparently allows the spike protein of the virus to bind more easily to cells to enhance transmission.

“Currently, there is no evidence to suggest that the variant has any impact on the severity of disease or vaccine efficacy,” the CDC emphasized.

Cases of the U.K. variant have been reported in California, Colorado, Connecticut, Florida, New York, Pennsylvania, Georgia, and Texas. The South African variant had not been detected in the United States as this report was filed.

Urging more vigilance with masks, social distancing, and hand hygiene, Walke said an increase in cases due to heightened transmissibility could hit a healthcare system that is running on the thinnest of margins in many areas.

“Because the variants spread more rapidly, they could lead to more cases and put even more strain on our heavily burdened health care systems,” he said.

The variant first seen in the U.K. — which is now spreading among people with no travel history in the United States — is 56% more transmissible than the original pandemic coronavirus, researchers report in a paper under review. 

“As a result of this increased transmissibility, existing control measures are likely to be less effective, and countries may require stronger proactive interventions to achieve the same level of control,” they concluded. “We found no evidence that the new variant is associated with higher disease severity, but without strengthened controls, there is a clear risk that future epidemic waves may be larger — and hence associated with greater burden — than previous waves.”