A new study of 18 states that exempt children from vaccination requirements for nonmedical reasons found these rates are rising among kindergartners in 12 states, including Oregon, Idaho, Utah, Texas, and Maine.
Even though vaccines have been widely proven to be safe, parents forego childhood immunizations for a number of non-medical reasons such as religious or philosophical beliefs. "In both instances, vaccine coverage declined due to organized anti-vaccine movements alleging that vaccines cause autism and other illnesses, despite overwhelming scientific evidence that there is no link".
Overall, eight of the top 10 counties with the highest NME rates were in Idaho. Most states require children to have up-to-date vaccinations to enroll in public schools.
In a report published Tuesday in PLOS Medicine, researchers from several Texas academic centers tracked the increasing number of children with exemptions in all 18 states from the 2009-2010 to 2016-2017 school years.
"As larger unvaccinated populations grow, particularly in highly mobile cities, the potential for vaccine-preventable disease outbreaks grows", said Peter Hotez, professor at Baylor College of Medicine and co-editor-in-chief of PLOS Neglected Tropical Diseases; and Melissa Nolan, an assistant professor of epidemiology at the University of SC, in a joint statement.
Vaccine-preventable infectious diseases like measles are now not widespread in the United States thanks to herd immunity - meaning the majority of people across the country have been vaccinated, which keeps outbreaks from spreading.
However, that changes the more people go unvaccinated.
At least 90 to 95 percent of people in the community need to be vaccinated against measles to provide what's known as "herd immunity".
"Stricter legislative action to close [non-medical exemptions from vaccination] should become a higher priority", the study concludes.