Non-medical exemptions from childhood vaccinations are rising in some areas of the United States, creating a risk of vaccine-preventable disease outbreaks, argue Peter Hotez, Melissa Nolan, Jackie Nolan, and Ashish Damania in a Policy Forum article in PLOS Medicine.
Eighteen US states currently permit non-medical exemptions from childhood vaccinations owing to "philosophical beliefs." The team from the National School of Tropical Medicine at Baylor College of Medicine and the Texas Children's Hospital Center for Vaccine Development analysed routine data from these states, and found an increase since 2009 in the number of children enrolling in kindergarten with a non-medical exemption in 12 of the states.
They identified several metropolitan areas across the country that stand out as "hotspots" of vaccination exemptions, including major metropolitan areas in the Pacific Northwest, Texas, Utah, and Arizona, as well as less populated and rural counties in Idaho. In a further analysis, the authors found that higher rates of non-medical exemptions in individual states were associated with lower rates of MMR (measles, mumps and rubella) vaccination coverage.
Highly infectious diseases
Hotez and colleagues emphasize the near-complete vaccination coverage — 90 to 95% — needed to protect children from highly infectious diseases such as measles, citing the 2014-15 outbreak in Anaheim, California that was associated with low vaccination coverage and led to a ban on non-medical exemptions in California.
"Stricter legislative action to close [non-medical exemptions from vaccination] should become a higher priority," the authors say. They also note: "Our concern is that the rising [non-medical exemptions] linked to the anti-vaccine movement in the US will stimulate other countries to follow a similar path."