A new coronavirus variant, first identified in the U.K. and recently found in Snohomish and Pierce counties, has been detected in a King County test sample, health officials announced Friday.

University of Washington Medicine on Friday notified King County public health officials, who said the news was “worrisome, but not surprising,” according to a blog post from Public Health — Seattle & King County

The variant, known as the B.1.1.7 strain, spreads more easily than others and quickly became the dominant strain in the U.K., King County health officials said. The Centers for Disease Control and Prevention predicted in a study last week that the strain will likely become the predominant one in the United States by March.

“As we confront this more contagious strain of COVID-19, here’s the important thing to understand: The variant strain spreads in the same ways as other COVID-19 strains, it’s just better at it,” the health department’s Friday post noted. “That means we need to get better at our countermeasures: masks, physical distance, good ventilation and staying home when possible.”

King County Health Officer Dr. Jeff Duchin said in the post that residents should expect the variant strains to become widespread here.

“But we have the advantage of early warning to help us prepare,” he said.


The variant was detected in a King County resident — who was not hospitalized — sometime this month, a county health spokesperson said Friday evening. No further information about the resident was immediately available.

As of Friday morning, the new variant had been detected in 24 states, including in two people in Snohomish County and one in Pierce County. The variant found in Snohomish County was detected through public health case and contact tracing and genome sequencing at the UW Medicine Clinical Virology Lab.

The variant first appeared in September 2020 and has spread throughout London and southeast England.

Dr. Umair Shah, state health secretary, has said it’s unclear how many cases the new strain is adding to the overall coronavirus infection rates in the U.S., and researchers will review that closely. Nationally, 417,394 people have died, and 24.9 million have been infected by the virus, according to the Johns Hopkins University tracker.

The variant discovered in the U.K. is about twice as transmissible as the coronavirus first identified in China, but isn’t any more lethal, Dr. Anthony Fauci, the U.S. government’s top infectious disease expert, told a national news conference last week. However, if it creates more cases, there would be more hospitalizations and deaths, he said.

“The appearance of the B.1.1.7 variant in Washington is a wakeup call,” the Friday post said. “It’s more important than ever to do all we can to stop the spread of COVID-19 … and to push cases down as low as possible BEFORE the B.1.1.7 strain can spread widely and gain an advantage. This means we need to meet this new challenge by going all in on the steps that we know work, starting now.”

Click here for more information about the new variant.

Information from the Seattle Times archive is included in this report.