A new study has identified the hotspots of philosophical and religious vaccine exemptions: the paperwork that (in some states) you can fill out in lieu of getting your kindergartener vaccinated. Most are in rural areas, but 15 mid-size cities have a dangerous combination of a large population and a high rate of these exemptions.


These are non-medical exemptions, by the way; all states allow medical exemptions for children with immune system disorders or other conditions that would make vaccines too risky for them. And ironically, those children who are unable to be vaccinated (and those who are too young to be vaccinated) are the most at risk from policies that allow healthy people to skip out on vaccines.

Why Hotspots Matter

One person can’t spread a vaccine-preventable disease by themselves. Imagine you go on vacation and catch measles, and then come home and start coughing on all your neighbors. If they’re all vaccinated, the disease won’t go far. (The measles vaccine is 97 percent effective for people who get both recommended doses.) A few vaccinated folks will be able to catch and spread the disease (3 percent of them in our example), but that’s just not enough people to sustain an outbreak. So that’s why it’s concerning any time there is an area with a lot of unvaccinated people—which is exactly how measles spread in Disneyland in 2015. You need a combination of a lot of people to cough on, and a high percentage of them unvaccinated.


The researchers who made the map above also looked for counties with more than 400 kindergarteners with non-medical exemptions. They found 15, and the largest cities in each of those counties are:

Phoenix, AZ (2,947 exemptions in 2016-2017)

Salt Lake City, UT

Seattle, WA

Portland, OR

Troy, MI

Provo, UT

Houston, TX

Fort Worth, TX

Plano, TX

Warren, MI

Detroit, MI

Pittsburgh, PA

Austin, TX

Kansas City, MO

Spokane, WA (405 exemptions)

If you’re suprised California didn’t make the list, that’s because after the Disneyland measles outbreak, the state passed a law eliminating non-medical exemptions. The next year, California saw an uptick in the number of kids who were supposedly medically unable to be vaccinated, but in total, exemptions went down and more kids got vaccinated.

But the fact is, there are likely more hotspots than just the ones on the list above. It’s not like anti-vaxxers marched their teenagers to the doctor the day California’s law passed; unvaccinated kids (and adults!) are still out there. There may be plenty of unvaccinated people in states that don’t have the exemptions, too, especially if state law makes it easy to get a not-entirely-honest medical exemption.