There are more than 600 kindergartners attending school in Wyoming with no vaccination against measles or polio, according to new figures released by the CDC. The CDC says this means the state has fallen below the threshold for herd immunity.
Across the country, kindergartners are less likely to be vaccinated for a wide range of diseases than they were before the pandemic. The new CDC data shows that MMR coverage — that's the vaccine for measles, mumps and rubella — has dropped from 95 percent before 2020 to 93 percent now. It's even lower in Wyoming, at 90.8 percent.
Epidemiologist and science communicator Katelyn Jetelina has worked as a scientific advisor, including for the White House. She said a 90 percent coverage rate might sound good enough, but because measles is so contiguous, communities need to hit a 95 percent threshold to achieve herd immunity.
Herd immunity is what protects those who, for medical reasons, cannot take the vaccine, such as newborn babies.
Wyoming is one of 36 states that fall below that threshold for MMR coverage. Kindergartner vaccine coverage for other diseases, including polio, has also gone down.
"I feel like we're moving backwards, slowly but surely," Jetelina said. "And this means we'll likely see the resurgence of infectious diseases that we once considered 19th century problems."
Jetelina analyzed the new CDC data for her public health newsletter, Your Local Epidemiologist. She said the drop in vaccine coverage is like a "slow, painful bleed" rather than a plummet, but there are now pockets of unvaccinated kids. Jetelina said these pockets are perfect breeding grounds for otherwise preventable diseases.
"The other interesting thing that kind of goes hand in hand with this is the role of exemptions and the significant increase in exemptions," she said.
Nationally, the number of kindergartners receiving non-medical exemptions went up. During the last school year, almost five percent of Wyoming's kindergartners had a medical or religious exemption that let them attend school unvaccinated.
Public health experts can't say for certain why there's been a rise in exemptions and a drop in vaccinations. But Jetelina said it's possible that growing acceptance of misinformation, schedule disruption during the pandemic, and a loss of trust in public health institutions all play a part.
"How much each of these are contributing to the decline in routine vaccinations and by how much is something we really don't have a good grasp on yet," she said. "What we saw during the pandemic was just this perfect storm of all these different factors. And unfortunately, children's health is getting directly impacted by it."
