At least 15 U.S. cities have “hot spots” of unvaccinated school-age children, according to a recent review of states that allow families to refuse required shots.
Such areas – highly concentrated with unvaccinated kids – are the result of a rise in the number of families granted nonmedical exemptions to opt out of vaccinations against diseases such as measles or whooping cough, according to a study published in PLOS Medicine, a peer-reviewed medical journal. Families seek such exemptions from school vaccination requirements on religious or philosophical grounds, but an increase in unvaccinated children has, in part, been tied to the medically discredited belief that vaccines cause autism spectrum disorder.
The analysis identified metropolitan areas where more than 400 kindergarten-aged children aren’t vaccinated. The areas, listed below, span the Northwest, Southwest, Midwest and Northeast. Here, the risk of contracting diseases is growing, the study suggests.
|Utah||Salt Lake City; Provo|
|Texas||Houston; Fort Worth; Plano; Austin|
|Michigan||Troy; Warren; Detroit|
Researchers analyzed vaccination data from the 18 U.S. states that allow nonmedical exemptions from childhood vaccinations and the Centers for Disease Control and Prevention, finding that 12 of those 18 states have shown an increase in the number of kindergarten-age children enrolled in schools with nonmedical exemptions since 2009. They analyzed data by academic year between the 2009-2010 and 2016-2017 school years.
The 12 states showing an increase in exemptions are: Arkansas, Arizona, Idaho, Maine, Minnesota, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Texas and Utah. The six additional states allowing exemptions are: Colorado, Louisiana, Michigan, Missouri, Washington and Wisconsin.
But large cities aren’t the only areas of the U.S. with high rates of nonmedical exemptions. At the county level, researchers identified 10 counties with more than 14 percent of their kindergarten-age children unvaccinated. Generally, the 10 counties with the highest nonmedical exemption rates in the country “have fewer than 50,000 persons and are located in rural regions of the state,” and eight of the top 10 were in Idaho, according to the findings.
“As larger unvaccinated populations grow, particularly in highly mobile cities, the potential for vaccine-preventable disease outbreaks grows,” said Peter Hotez and Melissa Nolan in a joint statement. Hotez is a professor at Baylor College of Medicine and co-editor-in-chief of PLOS Neglected Tropical Diseases, and Nolan is an assistant professor of epidemiology at the University of South Carolina.
Researchers are conducting a second study to better inform public health education campaigns aimed at increasing vaccinations.