Demand has been strong so far in Marin County for the pediatric Covid vaccine, newly available to young children this month. Officials are hopeful that parents, the vast majority of whom got the shot, will show up in the same numbers to vaccinate their 5- to 11-year-olds. But some parents in West Marin, where childhood vaccination rates have historically lagged, could take time to make the decision. 

“We’re seeing significant demand, which is reassuring,” Dr. Matt Willis, the county’s public health officer, told the Light. “But the timing is a little tight because we’re really eager to get our children vaccinated coming into the holidays.”

County health officials began administering the pediatric Pfizer vaccine on Nov. 3, the day after the Centers for Disease Control and Prevention made children as young as 5 eligible on an emergency basis. Last week, pediatricians began receiving doses to administer themselves. More than 3,000 children in that age group received the vaccine in Marin during the first week they were eligible, and by this week, the numbers are up to nearly 7,000. 

It’s a strong showing—25 percent of all eligible kids in two weeks—but it will need to continue in order to combat the latest increase in cases, which public health officials believe could sharpen when families gather indoors for the holidays. “The winter surge seems to be potentially real,” Dr. Willis said. “My concern is that the factors that are contributing to that rise now are going to persist through the coming months.” 

Severe Covid symptoms are uncommon in children under 11, and while hospitalizations went up for the age group during the summer surge, deaths remain extremely rare. Nonetheless, Dr. Willis said, vaccinating young children will help alleviate the latest wave of infections. Until this month, all 20,000 Marin kids aged 5 to 11 were unvaccinated, and none have yet received a second dose, which is administered three weeks after the first. More than 40 percent of the county’s infections among the unvaccinated are in children, though kids represent only 8 percent of the county’s population.

“That’s really a potential reservoir for the virus, to find a whole cohort of vulnerable people,” Dr. Willis said. “The way to close that gap is to vaccinate our kids.”

At the West Marin School last week, county health officials set up a clinic in the gym with enough vaccine for 150 pediatric doses. By the end of the day, they had administered 93. Kids got to pick out toys and vaccine-themed coloring pages, and “Finding Nemo” played on a widescreen T.V. while they waited the required 15 minutes to be monitored for side effects. 

As with any childhood vaccine, a few kids were visibly nervous. “I was really scared in the car, and I was looking left and right like, ‘Is someone gonna jump into the car with a needle and shove it into my arm?,’” said Alexa Heftye, a fourth grader from San Anselmo. “I was actually pulling my mom backwards when we were entering here.”

But Bolinas School fourth grader Fletcher Lucanic wasn’t bothered by the shot. “It was kind of like if you just got pinched,” he said. 

Galen Leeds, a Tomales resident, said he was relieved that his son, Corbin, could now get the shot, which would allow them to travel without worrying. Corbin, a preschooler at Little Sparrows in Point Reyes Station, turned 5 the day before the clinic. “We’ll feel a little better about going to visit my parents in Colorado,” Mr. Leeds said. 

At the other end of the age range, 11-year-old Tomales Elementary student Gael Aceves said he’d been very worried about getting Covid at school. Now, he said, “the chances of getting sick are way less.”

The comparatively low 10-microgram pediatric dose, one third of what adults get, reduces mild reactions like sore arms and flu-like symptoms, and the county has recorded no serious adverse reactions. Pfizer’s clinical trial found the lower dose to be 91 percent effective in preventing symptomatic infections among children. 

When the pediatric vaccine attains full regulatory approval, it will become one of the regular childhood vaccinations required to enter public or private school in California. According to school officials, that could happen by next fall. None of West Marin’s school districts have plans to require vaccinations for kids under 11 before the state mandate arrives.

The county would welcome a mandate, Dr. Willis said, but he hopes most parents will come to the decision on their own, before any requirement. “We don’t have that long, and we need to really optimize where we are right now, which is helping parents navigate to that choice,” he said. 

Marin was once known for relatively low childhood vaccination rates, with many parents applying for exemptions based on personal belief. Enclaves of under-vaccination held strong in West Marin until California did away with the personal belief exemption for childhood vaccines in 2015. 

In the 2013-14 academic year, San Geronimo Valley Elementary School, home to the Open Classroom program, reported among the lowest rates of up-to-date kindergarten vaccination in the county at 16 percent. Nearly all the valley’s unvaccinated families had filed personal belief exemptions, and only Marin Waldorf School and Marin Montessori School had lower rates. 

Two years later, after Senate Bill 277 eliminated personal belief exemptions, vaccination rates improved across the county. Ninety-four percent of the Open Classroom was vaccinated in the 2015-16 year—all but one student, who had a medical exemption.

“Once that law came down, a lot of people’s beliefs weren’t quite so strong anymore,” said John Carroll, superintendent of the Lagunitas School District. “People I thought would go to private school or homeschool or whatever, they showed up with their immunization records.”

It wasn’t just S.B. 277 that improved vaccine uptake in Marin in the last decade, Dr. Willis said. He suggested that the resurgence of preventable infectious diseases, which inspired the law, also prompted “soul searching” among Marin parents before the legislature ever put it into writing. In 2010, Marin had the state’s largest outbreak of pertussis, which is easily prevented by a vaccine and booster.

“That shifted the culture toward more vaccinations,” Dr. Willis said. “When S.B. 277 came in, we were already at about 88 percent. A lot of that gain was achieved when it was still an environment of choice.”

The trend has continued, and Covid underscored the urgency of vaccination for many parents. Mr. Carroll said almost all the middle schoolers in his two districts got the shot, and early anecdotal reports suggest the pediatric vaccine sites have been popular with valley families. Although personal belief exemptions will be available for the Covid vaccine, Mr. Carroll said he expects few parents to apply for them.  

“It’s a pretty big change from how things used to be,” Mr. Carroll said. “West Marin, especially in the San Geronimo Valley, was famous for a lot of anti-vaxx sentiment, at least in 2015.”

But that sentiment has not disappeared. Madeline Hope, director of the Tomales Bay Youth Center, said the predominant attitude among parents she knows is one of relief and enthusiasm, but “there are still those people in our community that are like, ‘I will never have my kids vaccinated for anything. You can’t make me.’”

Those deeply held anti-vaccine beliefs lie with a small percentage, said Dr. Anna O’Malley, who practices family medicine at the Coastal Health Alliance. A larger group may be parents who are vaccinated themselves but are hesitant to see their kids get the shot.

“Many parents have said, ‘I want my kids to get the vaccination, I just don’t want to be first in line for it,’” Dr. O’Malley said. “It’s not necessarily a scientific process, but there is something to positive peer pressure. It makes it easier to do something when you know that your kids’ classmates have had this positive experience.”

Glenda Mejia, the family advocate at West Marin School, witnessed that effect in action while talking to a parent at last week’s vaccination clinic. The woman’s teenage kids were already vaccinated, but she was initially concerned about her 6-year-old. “The whole day you could see the worry in her face,” Ms. Mejia said. “But she got the shot at the end of the day.”

Marin has among the highest Covid vaccination rates in the nation, with roughly 94 percent of the eligible population having received at least one dose. More than half of the county’s seniors have received a booster, which the C.D.C. has authorized for vulnerable populations. 

“The high vaccination rates in our community mean that most of us in Marin are approaching this decision as whether or not we want to extend to our children the protection that we’ve already chosen to gain for ourselves,” Dr. Willis said.