This Centers for Disease Control and Prevention (CDC) scientist was testing patients’ samples for SARS-CoV-2 antibodies, using the CDC serologic test. (James Gathany/CDC 2020)

Two cases of the United Kingdom variant of COVID-19 have appeared in Marin County for the first time, health officials announced Tuesday.

The B.1.1.7 variant, which is contributing to the recent coronavirus surge in eastern states and Europe, is officially a “variant of concern,” according to the U.S. Centers for Disease Control and Prevention. It’s more infectious than other strains and may lead to more severe disease.

“This variant has been detected across California,” said Dr. Matt Willis, Marin County’s Public Health Officer, in a statement. “Though it’s no surprise, the presence of this variant is not something to ignore. It’s a reminder, as we reopen, that we’re not out of the woods by any means. We need to stick with the tried and true prevention measures while we work to increase vaccination rates.”

Marin County is currently in the orange (moderate tier) of re-opening, according to state guidelines. Officials expect to open vaccinations to everyone 16 and over by April 15, though the county is dealing with limited vaccine supplies. Health officials say it may be three to four weeks before those seeking appointments can get one.

The county is working with six labs around the state to genetically sequence COVID-19 samples, to track the spread. So far, there have been no reports of other variants of concern in Marin, including those from South Africa and Brazil.

“The good news is the current COVID-19 vaccines are effective against the B.1.1.7. strain,” Willis said. “As of today, 61 percent of Marin County residents over age 15 are vaccinated with at least one dose. Every day we’re better prepared as a community. This finding increases the importance of obtaining a vaccine when you’re eligible.”

Officials caution people to keep wearing masks to minimize exposure and keep activities outdoors whenever possible. For updates on eligibility and vaccine appointment eligibility, go to