An increasing number of parents are opting out of school shots for their children, with more than one in 20 kindergarten children in public schools not getting the full vaccination required for attendance, writes the Associated Press.
With more vaccine exemptions being sought, health officials worried about outbreaks of diseases that would normally be under control.
"People frame this as a personal, private matter. And it's not," said Geoffrey Swain, associate professor at the University of Wisconsin School of Medicine and Public Health and chief medical officer for the Milwaukee Health Department.
"When we have parents who take a personal convictions waiver (so their kids don't have to get shots), it puts all these other kids who can't be vaccinated at risk, too. That's what makes me so angry and concerned."
Wisconsin is one of 10 states whose number of vaccine exemptions has increased over the past five years by over 1.5 percent. Wisconsin currently allows parents to obtain vaccine waivers because of "personal convictions" or for medical or religious reasons, the Associated Press found that exemption seekers are often middle-class, college-educated white people, but there are often a mix of views and philosophies.
Mandatory vaccination is a major issue in California. Last year, the state had more than 2,100 whooping cough cases, and 10 infants died. Only one had received a first dose of vaccine.
In the beginning of this year, the state allowed a 30-day delay before the law was put into effect. The medical community began using all means of communication at its disposal, including social media like Twitter and Facebook, to encourage vaccination to the families of all the 3 million children in the state.
Yet the Associated Press analysis found that more than half of states have seen a rise in the rate of exemptions over the past five years, with 10 having increases of about 1.5 percent or more, a range health officials say is troubling.
It's "really gotten much worse," said Mary Selecky, secretary of health for Washington state.
The states that have had the biggest were located almost exclusively in the West and Midwest – Alaska, Kansas, Hawaii, Illinois, Michigan, Montana, Oregon, Vermont, Washington and Wisconsin.