County of Marin - News Releases - Variant Detected

For Immediate Release
April 06, 2021

B.1.1.7 COVID-19 Variant Detected in Marin

Health officials urge use of face coverings and to seek vaccinations when eligible

San Rafael, CA – Two local cases of COVID-19 infection with the B.1.1.7 variant of SARS-CoV-2, first detected in the United Kingdom, have been reported by Marin County Public Health. As the county ramps up genomic sequencing of local COVID-19 specimens, this report signals the first reported cases associated with this variant in Marin County.

The B.1.1.7 variant is classified as a “Variant of Concern” by the U.S. Centers for Disease Control and Prevention because it is more infectious than other strains, and it may lead to more severe disease. The B.1.1.7 variant is contributing to surges of cases in Europe and the Eastern United States. Other emerging variants of concern include B1.351 (more common in South Africa) and P.1 (more common in Brazil). No cases infected with these variants have been detected yet in Marin County.

The County is actively working with six labs around the state to ensure a fraction of COVID-19 samples are genetically sequenced. The information is combined with data from across the region to track the potential spread of variants of SARS-CoV-2. Regionally, the proportion of cases that are linked to the more transmissible variants is climbing and signals a concerning trend.

“This variant has been detected across California. Though it’s no surprise, the presence of this variant in Marin is not something to ignore.” said Dr. Matt Willis, Marin County’s Public Health Officer. “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.”

As of April 1, there are 9,359 confirmed cases of B.1.427 and B.1.429 (first detected in California), 851 cases of B.1.1.7., 35 cases of P.1 and 10 cases of B.1.351 across the State of California.

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

Marin County continues to face limited vaccine supply. Last week, vaccine eligibility expanded to those age 50 and over – and on April 15 it will expand to those age 16 and over. More doses are needed to vaccinate all of those who are eligible, and health officials indicate it may be 3-4 weeks before a newly eligible vaccine seeker can obtain an appointment.

Meanwhile, everyone should continue prevention measures that have already proven highly protective against COVID-19. Non-essential travel is discouraged, and if anyone is traveling, they are urged to quarantine upon return if they are not vaccinated. Marin Public Health officials remind everyone that although many activities are now allowed, it remains critical for the community to minimize exposure. Community members should continue to wear a mask, maintain physical distance, keep activities outdoors instead of indoors, and get vaccinated when it’s their turn.

Visit for latest updates on eligibility and availability of appointments.


Laine Hendricks
Public Information Officer
County Administrator's Office

3501 Civic Center Drive
Suite #325
San Rafael, CA 94903
(415) 473-7496
Email: Laine Hendricks
County Administrator website