Although vaccines are among the safest, most effective ways to protect children from major communicable diseases, some parents still doubt this. As a result, some choose immunization schedules that defy science or refuse to vaccinate altogether.

If these parents were distributed randomly, their decisions would be less likely to harm others, especially babies too young for vaccination. But parents who use personal belief exemptions to avoid school vaccination requirements often live in the same communities, studies have found.

Read more: http://www.npr.org/blogs/health/2015/01/20/378630798/parents-who-shun-vaccines-tend-to-cluster-boosting-childrens-risk?utm_source=twitter.com&utm_campaign=health&utm_medium=social&utm_term=nprnews