School reopening is accompanied this year by unusually high outbreaks in whooping cough, and new research points to relaxed immunization requirements for entry to kindergarten as a potential cause.
In a study published online this afternoon in the Journal of Infectious Diseases, researchers from from the Hubert Department of Global Health at Emory University in Atlanta found rising numbers of medical exemptions, between 2004 and 2011, to vaccinations normally required to start school.
Medical exemptions are typically given to students with compromised immune systems, such as after chemotherapy—but these students still depend on broad coverage among the rest of the school population to be protected from childhood diseases. Nationwide, more than 87,000 incoming kindergartners received medical waivers to the vaccination requirements during the study period, but the waiver rates varied significantly among states, from as low as 263 per 100 000 children in states with strict guidelines to nearly double that—411 per 100,000 children—in other states, suggesting that schools and states may not be monitoring whether medical waivers are being given for appropriate health reasons.
Saad B. Omer, the senior investigator of the study on state vaccination waivers, concluded, "Medical providers, parents, school officials, and state health officials are responsible for ensuring that medical exemptions are actually medically indicated."
Pertussis—commonly known as whooping cough or the 100-days cough— provides an example of why this sort of trend data should make education policymakers sit up. A student with whooping cough on average misses at least a week of school, and it can spread rapidly on campus before symptoms are diagnosed. During one five-month outbreak in a Cook County, Ill. high school in 2006, the Center for Disease Control and Prevention found 33 students and one teacher came down with whooping cough and 159 students—nearly 4 percent of students—had to be sent home for potential illness. The CDC is now recommending an adolescent booster for the illness, after 46 states reported higher rates of infection and Washington state continues to fight an epidemic.