Study finds vaccine exemptions rise when easier to obtain

Emory University researchers published a study on Wednesday that found that more parents get medical vaccination exemptions for their kindergarten children in states in which they are easier to obtain.

The study, published in the Journal of Infectious Diseases, found that the number of medical exemptions was relatively low during the seven years studied. The rate was more than six times higher in states with easy medical exemption criteria when compared to states with harder criteria. When more parents get vaccine exemptions for their children, herd immunity can be reduced, presenting a threat to children with real medical contraindications to vaccines, CIDRAP News reports.

The authors rated three states as having difficult medical exemption criteria, 17 as having medium criteria and 30 as having easy criteria. The national total of exemptions grew from 11,277 in 2004-2005 to 13,952 in 2010-2011.

"The appropriate use of medical exemptions is important to maintaining sufficient herd immunity to protect those who should not be vaccinated due to medical contraindications," Saad B. Omer, the senior author of the study, said, according to CIDRAP News. "Medical providers, parents, school officials, and state health officials are responsible for ensuring that medical exemptions are actually medically indicated."

The authors said that high medical exemptions occurred in states with difficult non-medical exemption criteria and easier medical exemption criteria. The study suggests that parents seek out medical exemptions if they cannot obtain non-medical ones.

"Granting medical exemptions for invalid medical contraindications may promote unfounded vaccine safety concerns," Daniel A. Salmon and Neal A. Halsey, said, in an accompanying editorial, according to CIDRAP News. "Although states may wish to allow parents who make decisions based on poor science or perceptions to withhold vaccines from their children, these exemptions should be distinguished from valid medical exemptions."