Peter J. Hotez
An increase in nonmedical vaccine exemptions have been reported in 12 of the 18 states that allow exemptions for philosophical beliefs, with high rates of exemption observed in many metropolitan areas.
This rise in antivaccine activity may provide an opportunity for future outbreaks to occur, a circumstance that may leave the multitude of unvaccinated children at risk of contracting a preventable disease.
According to Peter J. Hotez, MD, PhD, director of Texas Children’s Hospital Center for Vaccine Development and dean of the National School of Tropical Medicine at Baylor College of Medicine, and colleagues, 18 states allow vaccine exemptions for philosophical beliefs, including Arkansas, Arizona, Colorado, Idaho, Louisiana, Maine, Michigan, Minnesota, Missouri, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Texas, Utah, Washington and Wisconsin.
One state — Missouri — does not allow exemptions for public schools but permits exemptions for child care facilities. All states but Louisiana and Minnesota also permit religious exemptions.
Once state-level data on nonmedical vaccine exemptions were gathered, the researchers investigated trends occurring between 2009-2010 and 2016-2017. The number of children entering kindergarten with documentation of nonmedical vaccine exemptions were compared with the number of kindergarten enrollments in each state to calculate the rate of exemptions. Most data were collected from MMWR reports and state health departments.
Although the CDC did not provide information regarding nonmedical vaccine exemptions for the 2010-2011 school year, 10 states included in the analysis collected individual data.
Nonmedical exemptions from childhood vaccinations are rising in some parts of the United States, creating a risk of vaccine-preventable disease outbreaks.
Hotez and colleagues observed an upward trend of nonmedical vaccine exemptions beginning in 2009 in 12 states: Arkansas, Arizona, Idaho, Maine, Minnesota, Missouri, North Dakota, Ohio, Oklahoma, Oregon, Texas and Utah, with the greatest increase in exemptions occurring between 2009 and 2014. Some of these states have demonstrated a slowing of exemptions; however, rates are still increasing in certain states like Arkansas, North Dakota, Ohio, Oklahoma, Texas and Utah.
“Parents are opting their children from vaccines because erroneous of beliefs that vaccines cause autism or other neurodevelopmental delays,” Hotez told Infectious Diseases in Children. “As a vaccine scientist, pediatrician and autism dad, I’ve been working to raise awareness that there is no link between vaccines and autism,” he said. “Despite these efforts, nonmedical exemptions are rising in the U.S. where antivaccine groups are well-funded and well-organized.”
When county-level exemption rates were assessed, eight of Idaho’s counties had the highest rates of exemptions: Camas (26.7%), Bonner (19.7%), Valley (18.2%), Custer (17.1%), Idaho (16.1%), Boise (15.6), Kootenai (14.9%) and Boundary (14.61%). Wisconsin’s Bayfield County had a vaccine exemption rate of 15.7%, and Morgan County in Utah had an exemption rate of 14.6%. Almost all locations were similar in that fewer than 50,000 people lived within these mostly rural areas.
However, the researchers noted that large metropolitan areas also demonstrated high rates of nonmedical vaccine exemptions. More than 400 kindergarteners obtained exemptions in the following counties: Seattle and Spokane, Washington (King and Spokane Counties); Phoenix, Arizona (Maricopa County); Salt Lake City and Provo, Utah (Salt Lake and Utah Counties); Portland, Oregon (Multnomah County); Troy, Warren and Detroit, Michigan (Oakland, Macomb and Wayne Counties); Houston, Fort Worth, Plano and Austin, Texas (Harris, Tarrant, Collin and Travis Counties); Pittsburgh, Pennsylvania (Allegheny County); and Kansas City, Missouri (Jackson County).
High rates of nonmedical vaccine exemptions in these metropolitan areas suggest that quickly spreading outbreaks of vaccine-preventable diseases among children are plausible. Hotez and colleagues wrote that the areas with the largest number of unvaccinated children have busy international airports, which may increase the likelihood of further infection.
Additionally, a significant inverse relationship was observed in states that had high rates of nonmedical vaccine exemptions and immunization with the measles, mumps and rubella vaccine. States that banned nonmedical exemptions, including Mississippi, California and West Virginia, had the highest uptake rates and the lowest rates of disease, the researchers said.
“Whereas measles was thought to have been eliminated from the U.S. in 2000, we have seen local outbreaks of this vaccine-preventable disease and others, like whooping cough, in recent years due to inadequate immunization coverage in schools,” the researchers wrote. “For instance, a child with a nonmedical exemption from the measles, mumps and rubella vaccine is 35 times more likely to contract measles than is a vaccinated child. Moreover, a child without the diphtheria, tetanus and acellular pertussis vaccine is three-times more likely to contract pertussis than is a vaccinated child.”
“Unfortunately, pediatricians are spending more and more time in their practices trying to convince vaccine-hesitant parents that vaccines are safe,” Hotez said. He mentioned that pediatricians should become aware of talking points surrounding the issue of vaccine hesitancy and how to educate parents about immunizations. – by Katherine Bortz
Disclosures: The authors report no relevant financial disclosures.