Health officials in the U.S. state of California said a patient there has been infected with a coronavirus variant first detected in Britain, and that it is likely more cases will be identified in the United States.
California is the second state with the COVID-19 variant strain, following a case in Colorado earlier this week.
As was true with the Colorado case, the California Department of Public Health said the person infected there also had no known travel history.
California Health and Human Services Secretary Mark Ghaly called the development “concerning” and stressed the importance of known methods of preventing coronavirus spread, such as wearing masks, social distancing, staying home and avoiding travel.
"It appears that this particular mutation does make the virus better at transmitting from one person to another," said Dr. Anthony Fauci, the top U.S. infectious disease specialist.
During an online discussion Wednesday with California Gov. Gavin Newsom, Fauci said virus mutations are normal, and that he was “not surprised” additional cases of the COVID-19 variant would be found in the country.
He also said the variant is not believed to cause more severe illness than earlier forms, and that vaccines already being deployed should be just as effective against it.
The United States has begun vaccinations of frontline health care workers and high-risk populations such as those living in nursing homes using two vaccines given emergency use authorization.
The vaccines will then be made available to other groups in the coming months.
Fauci said if the vaccination program progresses as it should through May, June and July, then by early fall there will be “enough good herd immunity to be able to really get back to some strong semblance of normality - schools, theaters, sports events, restaurants.”
The United States has recorded 342,000 COVID-19 deaths, including more than 3,700 on Wednesday, according to the Johns Hopkins Coronavirus Resource Center.