Study: Unvaccinated families live in clusters

Families with underimmunized or unvaccinated children tend to live in clusters, according to new research that points to how public health officials can best focus their messaging.

A study published in the journal Pediatrics identified five geographic clusters in California where more three-year-olds had missed at least one vaccine compared with the wider population.

{mosads}The finding came from an analysis of health records for 154,424 children in 13 counties who are insured through Kaiser Permanente Northern California, a nonprofit plan.

Lead study author Dr. Tracy Lieu suggested that the research might help prevent outbreaks of vaccine-preventable diseases that have reemerged in the United States.

“With tools like these we have much more power and ability to identify emerging issues than anyone would have 20 or 30 years ago,” Lieu told Reuters.

“If you know there is a cluster of undervaccination or vaccine refusal in a certain area, you may be more vigilant.”

California officials have identified undervaccination or vaccine refusal as a new public health threat. Whooping cough, mumps and measles are starting to cause problems throughout the state as the number of parents deciding not to vaccinate their kindergarteners grows.

While the Kaiser Permanente study did not identify why undervaccinated families cluster together or decide against immunizing their children, the study showed how public health officials can target prevention efforts.

About 18 to 23 percent of children in the five clusters were underimmunized compared with 11 percent of children outside the clusters, the research found.