Six weeks after California officials reopened the economy, the state grapples with the fourth wave of Covid-19. New statewide vaccination requirements were announced on Monday, July 26, and North Bay counties now urge residents to wear masks in public spaces.

On July 26, California became the first state in the country to require that all state and health care workers be vaccinated or submit to Covid testing at least once a week. Ten days earlier, Marin and Sonoma County health officials joined other Bay Area authorities to recommend residents wear masks indoors, although state and local regulations no longer require fully vaccinated individuals to do so. Napa County issued its indoor mask recommendation days later.

The delta variant, an especially contagious strain of Covid-19 first detected in India, is able to infect vaccinated people at a higher rate than previous strains, and has become more and more prevalent.

As a result, “variant” is now a misleading term, Dr. Matt Willis, Marin County’s public health officer, said. Similar to the trend statewide, it is now the dominant version of Covid-19, representing 80–90% of Marin’s new cases.

In California, the delta variant comprised 43% of Covid cases in June. Nationwide, the figure was 58%, according to the Centers for Disease Control. By late July, the delta variant accounted for nearly 83% of all new cases in California.

Although they now recommend wearing masks again, health officials are careful to highlight that getting vaccinated is the most important step residents can take.

“We’ve gotten a lot of mileage out of educating our community… Vaccination is by far the most important strategy, followed by face coverings in indoor public settings,” Willis said last week.

Dr. Sundari Mase, Sonoma County’s public health officer, mirrored the comments in a July 16 statement announcing the regional mask recommendation.

“After vaccination, masking is the next most powerful tool we have to protect ourselves and each other during this latest wave of infections,” Mase said. “Wearing masks, especially indoors and in crowded outdoor settings, will help us contain this more transmissible variant.”

So far, neither county has mandated the use of masks for vaccinated or unvaccinated people.

“I do not anticipate moving from our current stance of recommending masks to mandating them,” Willis said last week.

By Sunday, July 25, 62% of all Californians 12 and older were fully vaccinated. Meanwhile, 86% of eligible Marin County residents and 70% of Sonoma County residents had been fully vaccinated. Marin has the highest vaccination rate in the state and one of the highest in the nation.

Sonoma County had 1,040 active Covid cases as of July 25, the highest rate in the county since March. The first two weeks of July saw 10 deaths, out of a total of 329 deaths throughout the pandemic.

One Covid death occurred last week in Marin County, the first in the county in two months, with a total of 186 deaths throughout the pandemic. The county confirmed 327 active cases over the past two weeks, as of July 26.

Marin, one of the first counties to recognize the particular threat of the highly-transmissible delta variant, identified its initial case in April. The county has prioritized whole genome sequencing, the process that allows the identification of variants.           

Between 20–25% of all Marin cases occur in the totally vaccinated, according to Willis. These occurrences, known as “breakthrough cases,” are defined as a case in a person who was vaccinated two or more weeks earlier. There have been 177 breakthrough infections in the county. However, unvaccinated residents account for over 90% of all hospitalizations and 100% of all deaths in Marin.

Marin health officials have not seen a significant difference of risk for breakthrough infections based on the type of vaccination received.

While Marin and Sonoma counties have higher-than-average vaccination rates, recent outbreaks in both counties also show the ongoing risks—especially for vulnerable populations,   including people experiencing homelessness and children under the age of 12 who are not eligible to be vaccinated.

In early July, the Press Democrat broke news that 47 of 153 residents of Sam Jones Hall, Sonoma County’s largest homeless shelter, had tested positive for the delta variant.

The outbreak represented the largest known infection in the county’s unhoused population since the start of the pandemic. By July 26, the outbreak had spread to 107 residents and several staff members.

Sam Jones, which Catholic Charities of Sonoma County had operated at lower capacity throughout the pandemic, ran at 70% capacity by July. Less than half of the residents had been vaccinated.

Catholic Charities acknowledged that they had not required residents to provide a negative Covid test before being admitted to the shelter, but instead simply screened for symptoms. One resident of the shelter told the Press Democrat that the nonprofit had not enforced masking and other safety guidelines very strictly prior to the outbreak.

Marin County experienced two outbreaks of the delta variant in May. A cluster of 30 cases, all attributed to the delta strain, occurred in the neighboring towns of Fairfax and San Anselmo. Contact tracing did not find a superspreader event or a single identifiable source.

Our Lady of Loretto School, a private Catholic K-8 school in Novato, suffered a spate of delta variant infections beginning in late May. All those infected were unvaccinated, including some children who were too young to receive the vaccine. 

At this point, the unvaccinated—who have had months to obtain their vaccinations, which have been widely available at convenient times and locations—have made a decision to delay. Unfortunately, the vaccine-hesitant are now prolonging the pandemic, especially because the delta variant is highly transmissible.

“My concern is that people may misunderstand breakthrough cases as a sign that the vaccine is not effective,” Willis said. “In fact, the vaccine is highly protective against severe illness and death, even against the delta variant. Because this variant is more contagious and is spreading more quickly, it finds unvaccinated people. If they aren’t protected by the vaccine, we could still be at risk for surges of people coming into the hospital and preventable deaths.”