CDC warns that travel could spread British Covid-19 strain in U.S.

There also is no evidence to suggest that the strain could reduce the effectiveness of the Moderna and Pfizer vaccines now authorized for use in the U.S., CDC said.

Most people who have been in the U.K. within the last 14 days are already barred by the CDC from entering the United States; there are exceptions for U.S. citizens and green card holders, among others. But federal officials are already warning of the possibility that the virus is already in the U.S.

“You really need to assume it’s here already,” said Anthony Fauci, the government’s top infectious disease doctor, during an interview with “Good Morning America” on Tuesday.

The context: Dozens of countries suspended travel to and from the U.K. over the weekend amid growing concerns about the risk posed by the new strain. The U.S. has not announced any new travel restrictions.

“CDC is following the situation closely and actively assessing the implications of the new variant and response options with respect to international travel,” the agency said in a statement.

Scientists in Britain first discovered the variant in September through genetic sequencing of virus samples taken from U.K. patients. Experts are now raising alarm over how quickly it has spread throughout southeast England. The CDC’s brief cites reports showing roughly 6 in 10 cases reported in London are caused by the variant.

According to the European Centre for Disease Prevention and Control, the strain could be up to 70 percent more transmissible than other versions of the virus, which collectively have infected more than 77.5 million people worldwide and killed 1.7 million.

What’s next: The CDC said it is monitoring the situation in the U.K. and communicating with its EU counterparts. The U.S. agency, along with state and local health departments, are monitoring and studying virus transmission to detect any changes in the strains circulating in America.