Knox is a rural, hilly county about an hour northeast of Ohio’s capital, Columbus. There aren’t statistics on how many Amish live in the community, but church attendance suggests there are about 3,500 in the county, which has a population of 60,810, according to 2013 Census Bureau figures.



The Amish are a Protestant religious sect that grew out of the Reformation. The U.S. is home to almost 500,000 Amish, who still live largely as their forefathers did. While there are many variations among Amish churches, most eschew cars for horse-drawn buggies, dress plainly and avoid other modern conveniences.



“Neither I or any of our nurses had ever seen a patient with measles, but the cases we encountered on that first day were textbook,” said Jackie Fletcher, the director of nursing for the Knox County Health Department.



The county launched a massive public education and immunization campaign that officials credit with preventing the disease from spreading beyond the county’s borders, although a handful of cases were eventually reported among the Amish in neighboring counties. Makeshift immunization clinics were held in Amish businesses and among the farmsteads of the Plain people. There were no deaths as a result of the outbreak.



Dr. Art Reingold, the head of epidemiology at University of California at Berkley, said the vast majority of those exposed to measles will become ill.



“The perceived wisdom is that 90 percent or more of those susceptible individuals who are exposed will come down with measles, but it is not 100 percent. Few things in nature are,” he said.



Those who were exposed, like Yoder’s cousin Mary Nisley, were put in a 21-day quarantine. She and her siblings didn’t contract the disease, but she watched uncles, aunts and cousins become ill. “People were sick. Very, very sick. Four of my cousins were taken to the hospital. A couple of babies were taken. Some people lost about 20 pounds,” she said.



The Amish views about vaccines vary widely, and while the outbreak persuaded many in Knox to get vaccinated, some are still not sold. The Amish church holds no official position concerning vaccinations, instead leaving it up to parents to decide. A combination of lack of access and suspicion keeps some from being vaccinated. According to the Knox County Health Department, which doesn’t break down immunization rates for the Amish and non-Amish, as of 2014, 95 percent of the county was immunized against measles.



“The Amish we vaccinated were obviously more receptive and especially those who had witnessed families and friends affected by the disease,” Fletcher said. She said there is a population of more conservative Amish who are generally resistant to vaccines. “In contrast, we see Amish families who have their entire family vaccinated. A lot has to do with the church they belong to.”



James Cates, author of “Serving the Amish,” has studied how social service workers and medical professionals work with the Amish. He said their view on vaccines is driven by faith rather than aversion to modern technology.



“As outsiders looking in, we see a fatalism in Amish beliefs that stems from their understanding that God will protect them. To make excessive efforts to protect oneself is to demonstrate a lack of faith in that care. So for example, there was a distinct resistance to placing ‘Slow moving vehicle’ signs on buggies before the majority of Amish groups agreed to adopt this safety measure. Lightning rods on houses and barns, hardhats on constructions sites and smoke detectors are other examples of this concern for a lack of faith, as is vaccinating children,” he said.



There is also misinformation in the community about side effects of vaccines.



“In our church … we have heard of a lot of very bad side effects you can get from the vaccine. And that is why we don’t do it,” said Nisley. The scientific community has discredited any link between autism and vaccines, but that fear still holds sway among some Amish.



Still, hundreds of people lined up at Ivan Miller’s business, Mohican Wood Products, to be vaccinated during the height of the outbreak.



Yet even after surviving measles, Yoder still has mixed feelings on immunizations. “But,” he said, “I might get immunized if I were going to travel to another country where there is an outbreak of something.”



Some Amish believe their skepticism of vaccines isn’t unfounded. In 2005 five Amish children in Minnesota, for instance, contracted a strain of polio that was traced to an oral vaccine.



And a relatively small but vocal group of people in the U.S. continues to question the efficacy and safety of vaccines — not just the Amish.



Jennifer Scmid, a nurse who has practiced in Southern California for over 25 years, is one of them.



“Most people I know are not against vaccination per se,” she said. “We question the nonexistence of scientific studies validating the current vaccine schedule. We question injecting ingredients such as aluminum and formaldehyde into our babies, which are known to cause neurological poisoning and cancer, respectively.”



Those who resist vaccines often cite the sheer number of vaccines children must receive today, from measles to chickenpox to hepatitis B. However, Amesh Adalja, a senior associate at the Center for Health Security at University of Pittsburgh Medical Center and School of Medicine, said there isn’t scientific evidence to back up claims of negative side effects of vaccines.



“The human immune system is a complex feature of our bodies that is daily bombarded with an innumerable amount of foreign material from bacteria, viruses, fungi and the like. The number of vaccines we receive pales in comparison to the actual work that daily living puts the immune system through. There is no magic number for vaccines, and I wish we had more to conquer diseases like malaria, HIV, and hepatitis C,” said he said.