Immunization rates for Marin kindergartners have reached their highest levels since 2000, when the state began recording such data, with 93.2 percent of students across the county’s 73 schools meeting all required immunizations.

The boost in Marin mirrors an overall increase throughout the state, according to the California Department of Public Health’s annual assessment, which was released last week. Nearly 96 percent of all California kindergartners are vaccinated, a considerable rise from last year’s rate of 91 percent.

The vaccination rate in Marin has seen a steady climb; just last school year, 87.5 percent of Marin kindergarteners were recorded as fully vaccinated. (The lowest rate was during the 2012 school year, when 77.9 percent of kindergartners were fully inoculated.)

The rise has pleased county health officials, who have been educating parents about the need to prevent outbreaks of childhood disease. “Some parents have a new awareness that vaccinations are a decision that can impact the whole student body,” said Lisa Santora, a public health officer for Health and Human Services.

Ms. Santora pointed to a combination of motives that likely led to Marin’s vaccination rate increase, including the debunking of a 1998 study by former gastroenterologist Andrew Wakefield that initially proposed a link between autism and vaccines. Other factors include the reappearance of vaccine-prevented diseases, such as measles, and the implementation of Senate Bill 277 in 2016. That law eliminated personal and religious exemptions from immunization requirements for children in schools.

“Policy tipped the scale,” Ms. Santora said of S.B. 277.

The law denies school enrollment to any student who has not, by kindergarten and seventh grade, received vaccines against a list of communicable diseases. Unvaccinated students are barred from attending all public and private elementary and secondary schools, daycare centers, day nurseries, nursery school, in-home family daycares and development centers.

A recommendation from a licensed physician is required to obtain a medical exemption.

The law fueled a national debate about whether vaccines are safe for children, whether personal belief exemptions compromise public health and whether the rejection of those exemptions constituted a violation of parents’ freedom of choice.

A Lagunitas School District parent was one of 21 plaintiffs who last year sued the state of California and the state’s departments of education and public health to block the law. The suit claimed that S.B. 277 violated the right for all children to receive education by barring them from attending schools. Last summer, a federal judge in San Diego ruled in favor of the law, citing legal precedents that protect states’ rights to force vaccination in order to shelter the public from infectious disease.

Five vaccinations for kindergarteners are required by the state: polio; DTP, which fights diphtheria, tetanus and pertussis; Hepatitis B; MMR, which inoculates against measles, mumps and rubella; and varicella, the chickenpox vaccine.

In Marin, parents in the San Geronimo Valley in particular have long drawn attention for eschewing vaccines. Rates in the Lagunitas School District have been noticeably lower than the state average in recent years. In 2016, before S.B. 277 went into effect, 10 out of 17 kindergarteners in the Open Classroom program had filed personal belief exemptions from the vaccination requirement.

Elsewhere last year, two out of 10 kindergarteners at Bolinas-Stinson School filed personal belief exemptions, and no kindergarteners at the three elementary schools in Shoreline Unified School District filed exemptions.

In the San Geronimo Valley, the numbers have drastically changed. In the Open Classroom this year, 11 of the 13 kindergarteners are fully immunized, while two students have permanent medical exemptions. In the Montessori program, 11 out of 12 kindergarteners are fully immunized. One student has a personal belief exemption that began last year during transitional kindergarten and will be valid until seventh grade.

All 32 of Lagunitas Middle School’s seventh grade students are fully immunized.

“We are relieved that our immunization rates at Lagunitas increased significantly with the new legal requirements for kindergarten and seventh grade enrollment,” said Laura Shain, the district’s principal.

The state Department of Public Health said data on individual school immunization records for this year will be posted at a later date.

Across the country, the decision to refrain from vaccinating children has led to a resurgence of diseases thought to have been eliminated. “We are seeing diseases we weren’t seeing for many years,” Ms. Santora said.

An outbreak of measles at Disneyland in 2015 raised statewide concern for unvaccinated students; at that time, two cases were reported and treated in Marin, along with a total of 136 cases statewide.

Locally, doctors at the Coastal Health Alliance have sympathized with concerns about vaccines, while urging people to keep thinking about the issues.

In 2016, Dr. Anna O’Malley wrote an op-ed for the Light that acknowledged imperfections in immunization, such as their tendency to contain adjuvant materials to stimulate the immune system, but advocated for keeping the conversation open.

“Like many providers at Coastal Health, I believe that a slowed immunization schedule is a reasonable and safe approach toward minimizing theoretical risk. Furthermore, we do our best to stock immunizations with the lowest levels of aluminum and preservatives. We strive to provide collaborative, non-judgmental guidance within the context of the primary care relationship,” she wrote.