Over the past few decades, there has been a worrying trend in people opting out of vaccinating their children - despite overwhelming evidence to suggest that it's a terrible idea.
Study after study has proven that there is no link between vaccinations and autism (one of the main arguments put forward by anti-vaxxers), and that denying a person the necessary inoculations leads to a greater risk of certain health problems in later life.
Joshua Nerius, a 30-year-old software product manager, found this out the hard way three years ago when he was diagnosed with measles.
At first, a doctor prescribed him antibiotics to combat the rash and high fever, but they had no effect. This prompted the doctor to ask whether Nerius had been vaccinated against measles as a child, as anyone who had been immunised would have been safe from the illness as an adult.
When Nerius messaged his mother to check whether he had received the vaccine, she replied with a thumbs down emoji. He was furious.
Because of the severity of the disease, Nerius had to be kept in an isolation room at Northwestern Memorial Hospital. He was in extreme discomfort, could hardly walk without assistance, and - over the course of his illness - lost 25lbs.
"I felt horrible," he said. "It took a serious toll."
As well as being annoyed about his own illness, though, Nerius feels for all the children who have had to experience the pain and discomfort because of their parents' ignorance.
"It makes me so angry," he said. "My parents thought they were doing the right thing. They were persuaded by the anti-vaxxers."
Nerius is actually very lucky, though, as measles can kill. Before the introduction of a vaccine in 1963, 400 to 500 people in the United States died each year as a result of the disease.
And yet, there is a worrying amount of advocacy for vaccinations to be banned or avoided.
Darla Shine, wife of the White House communications chief, Bill Shine, recently tweeted that she wished her children had caught measles as she did when she was young. "Bring back our #ChildhoodDiseases they keep you healthy," she wrote - much to the horror and dismay of medical professionals.
"When Darla Shine talks about how great it was that she had measles as a child, what she forgets to mention is that she gets to tell her story because she's alive. The ones who died - we don't hear from them," said Dr. Paul Offit, director of the Vaccine Education Center at the Children's Hospital of Philadelphia. He remembers the measles outbreak in 1991, during which nine children lost their lives.
Really, with the understanding we have now, there is no need to be so wilfully ignorant about the dangers of the anti-vaxxer stance.
"The science on this has been settled. It's been solved," Nerius said. "When I look at where we are today, with people who are wilfully deciding to ignore the facts, it really frustrates me. I just don't understand the mindset of people who want to spread fear."
In this case, Nerius was able to make a full recovery but tragically, others in his position have not been so lucky.
