A study by the Oregon Immunization Program finds that unvaccinated children spread pertussis through their communities.
The study, published in the Journal of Pediatrics, looked at a pertussis — or whooping cough — outbreak from 2012.
It found that while more than 90 percent of Oregon children were vaccinated, that didn’t stop the disease from spreading.
Epidemiologist and study author Steve Robison said parents who are reluctant to immunize often socialize with people who share a similar reluctance. And that, he said, may provide a way for infectious diseases to spread.
Vaccine skeptics in Oregon have filed a series of seven initiatives for the November ballot. Among other things, the measures would repeal current childhood immunization laws and require the state set up a study of vaccinated versus unvaccinated children — to see if there's a link with autism.
The CDC has repeatedly said there is no link.