Immunization Rates Among CA Children Fall But Less So Than Nationwide As State Eschews Federal Guidelines

SACRAMENTO, CA — As vaccination rates fall in California and nationwide, the state is rejecting controversial Trump administration guidelines that critics contend will lead to even lower vaccination rates.

The move comes as the new school year starts for millions of children.

In 2024-25, the most recent year California Department of Public Health data was available, overall kindergarten vaccination rates reached 93.7 percent, down from 95.6 percent during the 2016-17 school year. Statewide kindergarten rates for specific immunizations were higher: 95.1 percent for required doses of diphtheria, tetanus and pertussis (DTaP), and 95.7 percent for varicella. Measeles, vaccination rates were 96.1 percent. The state's MMR vaccination rates outpace neighboring states, including Arizona and Oregon, which reported vaccination rates of 90 percent and 87 percent, respectively.

California's measles, mumps, and rubella (MMR) vaccine rates meet the Healthy People 2030 target of 95 percent to maintain a sort of herd immunity. Healthy People 2030 is a U.S. Department of Health and Human Services initiative launched in August 2020, which sets a 10-year goal to improve health and wellbeing.

Still, the California Department of Public Health has reported a sharp increase in confirmed cases of measles this year. So far this year, there have been 58 cases of measles, more than double in 2025 with 25 cases reported. Most of the cases of measles reported were children, and only four of the cases this year involved patients who were already vaccinated.

California law requires students to be vaccinated against contagious diseases, including measles, mumps and and rubella.

Toddlers are younger preschool aged children are even less likely to be vaccinated. Full vaccinations among 2-year-olds for diphtheria, tetanus, and pertussis, in California have been falling since 2020, when the full vaccination rate was 89 percent. In 2024, the DTaP full vaccination rate was 73 percent. Full vaccination requires children receive all four doses of DTaP.

California's DTaP coverage is below the Healthy People 2030 target of 90 percent.

Nationally, vaccination rates tell a similar story as the MMR vaccine has declined over recent years as the Trump administration continues to share misinformation about side effects of the vaccine and autism.

On Aug. 10, Trump issued a executive order pushing for childhood vaccinations spread across multiple healthcare visits, including administering the MMR vaccine as three separate shots. The president and Secretary of Health and Human Services Robert F. Kennedy Jr. announced the recommendations during a press conference in which they repeated claims that immunizations cause autism, a theory that has been debunked by extensive research.

According to federal data posted last week, the fraction of kids exempted from vaccine requirements rose to 4.2 percent, up from 3.6 percent the year before. Nationwide, that's an estimated 155,000 more children entering the 2025-2026 school year without protection from highly contagious but preventable diseases.

It’s the fourth consecutive year that the national average exemption rate has reached a record, and the vast majority are parents withholding shots for nonmedical reasons. Exemptions increased in 41 states and the District of Columbia.

Experts point to turmoil caused by federal health officials.

“The root cause of this is primarily because there’s so much chaos and confusion in vaccination recommendation systems in the last year or so,” said Dr. James Campbell of the American Academy of Pediatrics.

U.S. Health Secretary Robert F. Kennedy Jr. was a leading voice in the antivaccine movement before President Donald Trump put him in charge of federal health agencies. In the last 18 months, Kennedy and other federal officials have repeatedly tried to revise and reduce childhood vaccination guidance. Earlier this month, Trump called for revamped childhood vaccination recommendations that promote his discredited theory that childhood shots should be spaced out into separate medical visits.

Nationwide vaccination rates fell for many diseases

The CDC reported that 92.4 percent of 2025-26 kindergarteners got their required measles-mumps-rubella shots, down slightly from the previous year. Before the COVID-19 pandemic, the vaccination rate was 95 percent — the level that makes it unlikely that a single infection will spark a disease cluster or outbreak.

Vaccination rates also fell for polio, for the combination shot against diphtheria, tetanus and pertussis, and for the first dose of the vaccine against chickenpox.

The rate held steady for protection against hepatitis B. But that's a vaccine given shortly after birth, and it will take a few years before recent federal efforts to upend infant hepatitis B vaccine recommendations would appear in the vaccination rates of kindergartners, Campbell said.

The declining vaccination numbers were posted as the U.S. experiences its worst year for measles since 1991.

The numbers indicate that more than a quarter of a million children entering kindergarten are susceptible to measles, said Campbell, a University of Maryland researcher who is chair of the AAP's infectious diseases committee.

Those at-risk kids are not evenly distributed — concentrations of unvaccinated children are higher in some places than others, which helps explain why measles waves vary in intensity.

This is when public health officials typically tout vaccines' benefits

The CDC data is coming out as school, and health officials across the country are encouraging parents to get their children vaccinated as the school year starts.

“Back-to-school season is an important reminder that protecting our children’s health is both a shared responsibility and a shared goal,” North Carolina Health and Human Services Secretary Dev Sangvai said in a statement. “Vaccines help keep our children and teens healthy and in the classroom.”

In the past, the CDC has released the vaccination coverage data in its flagship publication, the Morbidity and Mortality Weekly Report. CDC officials usually speak to the trends and stress the importance of vaccinations.

But since the Trump administration took office early last year, the agency has posted the data online. This year, the agency issued a three-sentence statement that noted a small decline in vaccination coverage among children entering kindergarten and said: “CDC continues to encourage parents to discuss vaccination options with their doctors.”

Medical exemption rates are steady

Public health officials focus on vaccination rates for kindergartners because schools can be cauldrons for germs and launching pads for community outbreaks.

For years, those rates were high, thanks largely to school attendance mandates that required key vaccinations. All U.S. states and territories require that children attending childcare centers and schools be vaccinated against a number of diseases, including measles, mumps, polio, tetanus, whooping cough and chickenpox.

All states allow exemptions for children with medical conditions that prevent them from receiving certain vaccines. And most also permit exemptions for religious or other nonmedical reasons.

In the last decade, the percentage of kindergartners with medical exemptions has held steady, at about 0.2 percent. But the percentage with nonmedical exemptions has risen.

According to the CDC data, 17.5 percent of kindergartners had an exemption to one or more vaccines in Idaho in the last school year. But fewer than 0.5 percent did in Connecticut.

The Associated Press contributed to this report.