(HealthDay News) — A physician-targeted communication intervention does not reduce maternal vaccine hesitancy, and schools with high levels of personal belief exemptions (PBEs) are often colocated with schools with elevated personal medical exemption (PME) rates, according to two studies published online June 1 in Pediatrics.
Nora B. Henrikson, PhD, from the Group Health Research Institute in Seattle, and colleagues enrolled 347 mothers of healthy newborns from 56 clinics in a randomized trial. The researchers found that maternal vaccine hesitancy decreased from 9.8% at baseline to 7.5% at follow-up in the physician-targeted communication intervention group (30 clinics), and from 12.6 to 8.0% in the control group (26 clinics). There was no detectable effect for the intervention on maternal vaccine hesitancy (adjusted odds ratio, 1.22; 95% confidence interval, 0.47–2.68).
Margaret Carrel, PhD, and Patrick Bitterman, from the University of Iowa in Iowa City, matched data for PBE and PME for California kindergarten classes from the 2001/2002 to 2013/2014 school years with locations of schools. The researchers found that when PBE cluster assignments were mapped, distinct spatial patterns were observed in California. Schools belonging to the “high PBE” cluster were spatially buffered from schools in “low PBE” and “medium PBE” areas. There was a positive correlation for PBE rates and the percentage of white students, charter status, and private schools.
“Hotspots of high PBE schools are in some cases colocated with schools that have elevated PME rates, prompting concern that herd immunity is diminished for school populations where students have no choice but to remain unvaccinated,” Carrel and Bitteran write.
The Henrikson study was funded by the Group Health Foundation.