Geographic hot spot analysis of vaccine exemption clustering patterns in Michigan from 2008 to 2017.

Objective: This study explored vaccine exemption clustering in Michigan and examined whether vaccine exemptions clustered by exemption type (medical, religious, and philosophical). Furthermore, the study investigated whether Michigan's nonmedical vaccine exemption policy change had an impact on type-specific vaccine exemption clusters following its implementation.

Methods: The study used the ArcGIS optimized hot spot analysis tool to visually examine vaccine exemption clustering by type in Michigan.