P0010 - An Examination of Miami-Dade County Public-School Vaccination Compliance Utilizing GIS Mapping

Background: As childhood immunization rates decline and school immunization exemptions rise, vaccination surveillance is essential for preventing communicable disease outbreaks. Geographic epidemiology is under-utilized in tracking childhood vaccine uptake. This study sought to identify areas at high-risk for vaccine-preventable disease (VPD) outbreaks in Miami-Dade County by mapping public school vaccination data.

Methods: Yearly vaccination reports from the Florida Department of Health were analyzed for trends in total vaccination and exemptions from 2013-2019. Additionally, a 2017-2018 report of public-school vaccination data in Miami-Dade was analyzed for similar trends. A map of this data was created with ArcGIS Pro software to assess for geographic clusters of public schools with low vaccination rates.

Results: Florida state and county-level vaccination data indicate vaccination compliance near or above the state goal of 95%. Miami-Dade County has not reached this goal for three consecutive years, with rises in religious exemptions. Miami-Dade 2017-2018 public school vaccination data demonstrates wide variability in vaccination compliance by school, with over half of schools under 90 percent. GIS map analysis demonstrated several clusters in Miami-Dade containing several schools with total vaccination percentages <90 percent, signifying high risk areas for an outbreak (Figure 1.) Additional statistically significant (p<0.01) hot spots were identified for high numbers of religious exemptions.

Conclusions: Although state and county-level vaccination data suggest good compliance in Florida, individual Miami-Dade public school data differ. This discrepancy reveals elevated risk for VPD outbreaks in populous areas is not adequately portrayed by the county vaccination averages. Spatial mapping of school-level vaccination compliance is a useful method to demonstrate clustering of schools with low vaccination to target for intervention.