TOP TAKEAWAYS
- Sixteen California counties have fallen below the herd immunity marker against measles, one of the world’s most contagious diseases, amid a sprawling outbreak.
- A rise in vaccine skepticism stemming from pandemic discord, experts warn, may be driving the decline.
- School nurses and doctors are often on the front lines of battle to explain the need to immunize against once-controlled diseases.
Before the pandemic, Lillian Lopez never questioned the safety of vaccines. That’s why all her children are up to date on their immunizations. The Bakersfield mother of three used to be religious about getting her flu shot. She never missed a year.
No more. Lopez, 45, took offense at how Covid-19 vaccine mandates and restrictions were enforced. The experience gave her pause about the integrity of the entire public health apparatus. Now, she questions every shot.
“I do have doubts, I don’t have the trust that I did in the past,” said Lopez, who also feels safer from infectious diseases in Kern County than in a more populous area. “I think it put fear in a lot of people. All this time, we’ve been trusting the CDC, the health organizations, but can we really trust them?”
Against the backdrop of this rise in vaccine skepticism, California reported a drop in the rate of kindergartners immunized against measles last year, fueling fears that there may be a resurgence of the once-vanquished disease amid the deadly outbreak in West Texas. One of the world’s most infectious diseases, measles can be spread by breathing in air exhaled by someone else. While there have only been nine cases reported in California thus far, Texas is now the epicenter of a spiraling outbreak with 712 cases, including the first deaths linked to the disease in a decade.
“It’s tragic,” said Monica Gandhi, an infectious disease expert at UCSF. “This is not a disease you want your child or you to get. This can be very dangerous. So, it is terribly important for us to combat vaccine skepticism right now.”
While California’s childhood immunization rates are still high compared with the rest of the nation, 16 counties have fallen below the threshold for herd immunity against measles, according to the California Department of Public Health. Last year, 96.2% of California kindergartners and transitional kindergartners were vaccinated against measles in the 2023-24 school year, down from 96.5% the year before. Only 93.7% of kindergarten students were up to date on all their immunizations, down from 94.1% the year before.
Holding the line on herd immunity is key to preventing the disease from sweeping through a community, experts say. This widespread protection also shields those who may not be able to get vaccinated for health reasons. This is key because while measles is most commonly associated with fever and rash, severe cases have been known to cause pneumonia and encephalitis. The disease can be lethal, killing about one to three people for every 1,000 infected.
Amid that context, nearly two-thirds of counties reported immunization rates for all childhood diseases below 95%, the rule of thumb for herd immunity, according to the California Department of Public Health.
Working with parents who deeply mistrust the safety of routine immunizations has become one of the most challenging parts of running a school vaccination clinic.
“Within this political landscape, there are some people who are hesitant,” said Susan Sivils, lead nurse for the Sacramento City Unified vaccination clinic. “Some worry that the vaccines are not safe. They don’t trust what’s in it, or they don’t trust where it was manufactured.”
Many of the lowest immunization rates can be found in Northern California, largely clustered around the Sacramento area, but Southern California has hot spots as well. Less than 81% of kindergarten and transitional kindergarten (TK) students were inoculated against measles in El Dorado and Glenn counties. Sutter County posted the lowest vaccination rate for measles, at 75.8%.
Another key trend is that charter schools had lower vaccination rates than traditional public schools, 76.41% compared with 92.07%, for measles last year. While they require routine childhood shots, experts say charter schools operate under strict admission and disenrollment laws that can make it hard to enforce the rules.
“These prohibitions make it very difficult for charter school staff to administer the vaccination mandate,” said Eric Premack, founder and CEO of the Charter Schools Development Center in Sacramento.
The bottom line is that consensus about vaccinations can no longer be taken for granted. To calm any fears, Sivils always hears parents out. While most are still comfortable with vaccines, one mother felt terrified that the shots would poison her child.
“I try to meet parents where they are,” said Sivils. “They are fearful, they are worried, they are upset, but, at the heart of it, they are trying to protect their family and do what’s best for their child.”
Declining trust in public health institutions has emerged as a watershed issue, experts say, as Covid-era controversies have sown seeds of doubt about the validity of science in general and vaccines in particular.
“The public health establishment during the pandemic said many things that didn’t turn out to be true,” as newly sworn-in National Institutes of Health Director Jay Bhattacharya, a professor of medicine at Stanford, has put it. “A much larger set of people who never previously thought twice about vaccinating their children are now in a position where they say, ‘Look, I don’t trust you guys anymore.’”
The cost of that inconsistency may be credibility now, Gandhi says, explaining why the anti-vaccine movement seems to be accelerating just as one of the nation’s most prominent vaccine skeptics, Robert F. Kennedy Jr., takes the helm of the Department of Health and Human Services. Families who learned to distrust guidance around the need for prolonged school closures and shuttered playgrounds, for instance, may now avoid vaccines altogether, often preferring home remedies.
“We had the most political response of any country, and that kind of political decision-making, as opposed to scientific decision-making, was noticed by the public,” said Gandhi, an expert in epidemics. “And then suddenly you don’t trust your public health official when they say the measles vaccine works, which by the way, it does.”
Indeed, some measles patients in Texas have shown signs of vitamin A toxicity. Notably, Kennedy had championed vitamin A to prevent measles, before reversing course to endorse the MMR vaccine, but overuse of the vitamin may have health consequences, such as abnormal liver function, and experts say there is no evidence it can protect against measles.
However, there is a grain of truth to the vitamin A advice, Gandhi notes. In the past, vitamin A deficiency did lead to more severe cases of measles, but today most people get a sufficient dose in their diet.
“You have to address that kernel of truth,” said Gandhi. “You have to say what happened with vitamin A historically, but now there’s no way we’re going to vitamin A our way out of this measles outbreak in West Texas.”
Sivils agrees that hearing people out is key. Citing evidence rarely seems to work at her clinic, but building a sense of trust often does.
“You have to respect people as parents, respect them as individuals,” said Sivils. “I make sure they know that I wouldn’t be doing this job if I didn’t believe I was helping people, but, at the end of the day, I allow parents to make their choice.”
Some families don’t approve of vaccines but get them anyway, so that their children can attend school, she says. Some spread the shots out over extra visits for fear of overloading their child’s immune system. Some research the ingredients in a vaccine before agreeing to it. Others decide to forgo vaccinations entirely and homeschool their children instead.
“You can’t railroad people,” she said. “I don’t try to persuade them. I just lay out all the options and let them make a decision.”
In Kern County, the measles immunization rate among kindergartners was almost 91%, below the herd immunity marker.
Lopez, for one, has no qualms about long-established vaccines such as measles, but she believes that people should always have the right to choose. She feels that right was trampled during the pandemic, and the affront still stings.
“When the vaccines were really being forced and people’s livelihoods were being threatened, I don’t agree with that,” said Lopez. “To me, that’s unethical, it’s an abuse of power.”
Given the ease of transmission with measles, which lingers in the air, some education experts worry what may happen to classrooms, where children often huddle together in tight spaces, should vaccination rates continue to fall. Whooping cough cases are also spiking now. Two infants in Louisiana are among the recent deaths caused by the resurgence of that disease.
“Our top job is to keep children safe,” said Scott Moore, head of Kidango, a nonprofit that runs many Bay Area child care centers. “The disruptions to child care, which would need to close temporarily every time a measles case occurred, would cause chaos for families and their employers.”
Deep partisan divides, experts warn, are leading families to extreme responses that may have extreme consequences.
“Our politics have become so divisive,” said Moore, “that what was once largely accepted as common sense — vaccination against deadly, infectious diseases — is now used to divide and conquer, with little children, once again, being the biggest losers.”