As states grow further apart on exemptions, 1 in 12 Ohio kindergartners skip their shots.
This year’s back-to-school season coincides with the worst measles resurgence that the nation has seen since the disease was declared “eliminated” nearly two decades ago.
At least 1,241 people — many of them school-age children — contracted the viral infection across 31 states so far this year, according to the most recent count by the Centers for Disease Control and Prevention, which called it the highest number of reported cases in nearly a generation.
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The rise comes amid increased demand for vaccine exemptions as parents, concerned about government control or worried about the now-debunked link between immunization and autism, seek to opt their children out of the mandatory shot schedule.
Some states are starting to crack down on the exemptions in response to measles outbreaks; others are considering offering parents even more ways to opt out.
About 200,000 kindergartners across the United States entered school without their measles vaccination in 2017, according to the latest CDC data available.
In seven states, the percentage of kindergarten students who are unvaccinated for measles is almost twice the national average of 5.9%, according to state figures compiled by the CDC.
Colorado, Idaho, Washington, Alaska, Arkansas, New Hampshire and Kansas all reported that at least 1 in 10 kindergarten students had not received the vaccine for measles, mumps and rubella, commonly referred to as the MMR vaccine.
In Ohio, the CDC says 8% of kindergarten students were unvaccinated for measles.
But those broader figures can obscure pockets of low immunization rates where outbreaks can occur.
Even states with seemingly high vaccination rates might include individual schools in which as many as a quarter of students are unvaccinated, according to data from states that make that information available, as well as academic research based on public records.
“What we find is that there are communities that are being swayed by anti-vaxxers,” Diane Peterson, associate director of the nonprofit Immunization Action Coalition said of groups advocating against vaccines. “They are persuading parents there is possibly harm to come from vaccines,” despite decades of medical research establishing their safety.
State laws vary
School vaccinations long have been a critical tool for combating infectious diseases such as measles.
Because most children attend a public or private school, most must be vaccinated under state laws.
All states allow exemptions for children medically unable to receive vaccinations. But 45 states also allow exemptions for personal or religious beliefs, which experts believe have contributed to the rise in measles outbreaks.
One of the largest measles outbreaks in the past 25 years occurred in 2014 and was centered in Ohio’s unvaccinated Amish population. Hundreds were sickened, and federal officials sounded a national alarm to urge people to get vaccinations.
Differing state laws lead to the varying state vaccination rates.
Take Texas, for example. Vaccine exemptions in that state grew 28-fold since a 2003 law making it easier for parents to opt out, according to a study published in August in the Journal of the American Medical Association.
The study showed how the rise in unvaccinated Texas schoolchildren heightens the risk for a major measles outbreak. Its computer simulations revealed that a single student with measles could start an outbreak infecting more than 400 people.
That’s why at least five of the nation’s largest professional groups for doctors, including the American College of Physicians, have supported eliminating or tightening exemptions.
“Allowing exemptions based on non-medical reasons poses a risk both to the unvaccinated person and to public health,” said then-ACP President Wayne J. Riley in a 2015 prepared statement.
Ten states considered bills this year to end non-medical exemptions for childhood vaccine requirements. Only New York and Maine approved the measures wholesale. Washington approved it just for the MMR vaccine.
California ended its non-medical exemptions in 2015.
But several states this year considered doing the opposite. Of a combined 64 bills related to childhood vaccine requirements, 13 would have made it easier to receive an exemption and 21 would have required doctors or schools to provide parents with information about vaccine safety or perceived hazards. None passed.
The National Conference of State Legislatures tracks vaccine-related proposals, but reported that none was considered by state leaders in the most recent session in Ohio.
The spread of measles often starts among unvaccinated children, who then transmit the disease to other unvaccinated children, who then pass it on to someone else, said Daniel Salmon, former vaccine safety director for the U.S. Department of Health and Human Services and current director of Johns Hopkins University’s Institute for Vaccine Safety.
A high fever, cough, runny nose and watery eyes precede the disease’s iconic rash. Many people with measles also experience ear infections, which can cause permanent hearing loss.
Other potential serious complications include pneumonia and brain swelling. Some, particularly infants and people with compromised immune systems, can suffer permanent brain damage or die from lung or neurological complications.
People who contract measles do not develop symptoms until one or two weeks after they became infected, meaning that they can unknowingly spread it to others before becoming ill themselves.
At risk are the 3% of the population for whom the vaccine fails, as well as those not vaccinated because they’re too young or have a compromised immune system or for other reasons. Those people, too, can spread the disease before anyone knows measles has entered the community.
If enough people are vaccinated, the disease struggles to spread beyond the initial person or family.
That’s called “community immunity” or “herd immunity.”
When community immunity is compromised, measles can spread easily and rapidly, said David R. Sinclair, a University of Pittsburgh public health researcher who worked with the Texas chapter of the American Academy of Pediatrics on the August study.
“Anyone who makes a decision not to vaccinate their children based on personal or religious beliefs,” Sinclair said, “is making a decision that has implications for the wider community.”