This story originally appeared in Stateline, an initiative of The Pew Charitable Trusts.
Child vaccination rates dipped into dangerous territory during the first year of the COVID-19 pandemic, when schools were shuttered, and most doctors were only seeing emergency patients.
But instead of recovering after schools reopened in 2021, those historically low rates worsened, according to new data from the federal Centers for Disease Control and Prevention. Experts fear that the skepticism of science and distrust of government that flared up during the pandemic are contributing to the decrease.
According to today’s data, the percentage of U.S. children entering kindergarten with their required immunizations fell to 93% in the 2021-22 school year, 2 percentage points below recommended herd immunity levels of 95% and lower than vaccination rates in 2020-21, when many schools and doctor’s offices were closed.
“While 1 percentage point might not seem concerning, that one percent represents tens of thousands of children who are inadequately protected from diseases we can easily prevent through immunization,” said Dr. Michelle Fiscus, chief medical officer at the Association of Immunization Managers, a nonprofit group of state officials who direct vaccination efforts.
“This national trend is alarming, especially as we see outbreaks of measles in Ohio among children who are too young to be vaccinated and those who are inadequately vaccinated. We need all hands on deck to get these children protected,” Fiscus said.
Public health officials warn that unless child vaccination rates for measles, chicken pox, polio and other diseases are quickly brought back to pre-pandemic levels, outbreaks of preventable diseases — like the measles outbreaks in Ohio and Minnesota in the fall and the polio case in New York last summer — are likely to become commonplace.
While COVID-related disruptions in schools and the health care system may be the primary cause for this recent drop in immunization rates, they’re only part of the reason state-required vaccination rates are trending downward, public health experts say.
They say the politicization of public health and increasing distrust of government have skewed parents’ previously positive attitudes about vaccines for measles, mumps, rubella, chicken pox, tetanus, diphtheria, polio and other childhood diseases that have been all but eradicated.
“I’m trembling in my anxiety about this,” said Dr. William Schaffner, a professor of preventive medicine at the Vanderbilt University School of Medicine.
“Our own success in immunizing children routinely, uniformly against a whole list of diseases that used to be common has resulted in the current generation of moms and dads not knowing much about these diseases, if anything,” he said.
“If you don’t fear the disease and respect the vaccines,” he added, “you may not adhere to state laws requiring them.”
In general, the public’s willingness to follow public health requirements has been waning since the COVID-19 pandemic began, said Dr. Marcus Plescia, chief medical officer at the Association of State and Territorial Health Officers.
The political divisiveness that erupted over COVID quarantines, masking and vaccines, he said, may be spilling over into what has been a widely accepted public health policy of protecting children from infectious diseases.
The CDC estimates that vaccinating children born from 1994 to 2018 will prevent 472 million illnesses, nearly 30 million hospitalizations and more than a million deaths. The state-run vaccination programs are also projected to save $479 billion in health care and other direct costs.
In 2019, a single measles outbreak of 72 cases in Washington state cost $3.4 million, CDC researchers estimated, with most of the costs incurred by local public health agencies.
State immunization rates vary widely. For the 2021-22 school year, Alaska, the District of Columbia, Wisconsin, Georgia, Idaho, Kentucky and Ohio had the lowest rates. New York, Rhode Island, West Virginia, Delaware, California, Massachusetts and Nebraska had the highest rates.
All 50 states and the District of Columbia require children to be vaccinated for childhood diseases before entering kindergarten, whether at a public or private school. Every state allows medical exceptions, and most allow parents to seek an exemption for religious or philosophical reasons.
Public health officials argue that the best way for states to boost their child vaccination rates is to enact ironclad vaccine mandates with no exceptions other than for medical reasons, such as for children who are undergoing cancer therapy.
Mississippi and West Virginia, which have such strict vaccine mandates, have had among the highest vaccine rates in the nation for decades.
California did away with its non-medical vaccine exemptions in 2015, followed by Maine and New York in 2019 and Connecticut in 2021. West Virginia’s vaccine mandate never included non-medical exemptions, and Mississippi’s law was stripped of non-medical exemptions in 1979 after the state Supreme Court ruled them unconstitutional.
California repealed its non-medical exemptions in reaction to high-profile measles outbreaks in 2014 and 2015, including one that started at Disneyland. After the law took effect, measles, mumps and rubella coverage rose by 3.3%, which put California closer to the herd immunity vaccination threshold of 95% for measles.
With most state vaccine mandates in place by the 1980s, the CDC declared victory over measles in 2000.
But in recent years, the diagnosis numbers have crept upward: In 2014, 667 measles cases were reported to the CDC. In 2019, state health departments reported 1,274 measles cases.
Even so, childhood vaccination rates in the United States remained high relative to other developed countries, and public attitudes toward routine childhood vaccines were relatively positive.
But since the COVID-19 pandemic began, state vaccine requirements have met more opposition. In October, a poll conducted by the Harvard Opinion Research Program showed that support for vaccination requirements to enter school had slipped to 74%, compared with 84% in 2019.
A similar survey published by the Kaiser Family Foundation in November showed that 28% of respondents said parents should be able to opt out of vaccinating their school-age children even if it results in health risks for others.
That’s up from only 16% who responded the same way in a 2019 poll conducted by the Pew Research Center. (The Pew Charitable Trusts funds the center and Stateline.)
In the past two years, dozens of bills have been proposed that would make it easier for parents to opt out of routine vaccinations for their school-age children, as well as COVID-19 shots, according to the National Conference of State Legislatures, which tracks state legislation.
In 2021, Kentucky and Florida enacted laws allowing parents to refuse routine vaccinations and still enroll their children in school.
Enforcement and Access
In addition to tightening vaccination mandates, public health officials say some states need to better enforce their rules and increase education and community messaging, so parents better understand the importance of vaccinating their children.
Measles, for example, is far more contagious than COVID-19. It typically infects 9 out of 10 people an infected person encounters, and the contagion can linger in a room for at least two hours after an infected person leaves.
Although most measles cases resolve within a week, it is a potentially life-threatening respiratory disease that often results in hospitalization. In Ohio, for example, 33 of the 82 children with measles last year were hospitalized.
Dr. Anne Zink, chief medical officer for Alaska’s Department of Health and president of the Association of State and Territorial Health Officials, said improving access to pediatricians, family doctors and other health professionals who can administer childhood vaccines is another way states can get more children vaccinated.
Pediatricians and family doctors typically provide immunization shots to children between 12 and 23 months. But for children who miss their vaccinations in their first two years and need to get caught up, some states set up local vaccine drives at schools and use mobile vaccination units to serve local communities.
Matt Guido, research coordinator for Dr. Ezekiel Emanuel at the Department of Medical Ethics and Health Policy at the University of Pennsylvania, said states should consider taking advantage of the infrastructure established for ramping up COVID-19 vaccinations and call on some of the same community leaders to help parents get their kids vaccinated before they start school next year.