Kyusik Kim (Ph.D. Geography), and Mark Horner, Ph.D., Professor of Geography at Florida State University, co-authored an article in the journal Annals of GIS titled, “Assessment of Disparities in Spatial Accessibility to Vaccination Sites in Florida” with Mahyar Ghorbanzadeh and Eren Ermen Ozguven, Ph.D. Below is a summary of the article written by doctoral student Martin Gandur (Ph.D. Political Science’ 25).
In “Assessment of Disparities in Spatial Accessibility to Vaccination Sites in Florida,” Kyusik Kim and Mark Horner, Ph.D., examined whether during the early COVID-19 vaccination stage, access to vaccination sites for older Floridians varied across individuals’ race, ethnicity, and income level.

To examine potential disparities in accessibility to vaccine distribution sites, the authors identified vaccination sites as of March 2021 and geocoded their addresses. The authors also employed census tract level data from the American Community Survey 5-year estimates to identify people 65 and older in the state of Florida as well as their race, ethnicity, and income levels.
Moreover, to calculate the distance between older subpopulation groups and vaccination sites, the authors employed hexagon-based spatial accessibility using Uber’s Hexagonal Hierarchical Spatial Index. This approach allowed the authors to compute highly disaggregated spatial accessibility to vaccination sites, since the size of the hexagon is smaller than the census block. Using this method, the authors calculated two accessibility measures: travel time to the nearest vaccination facility (nearest opportunity) and the number of facilities within a 15-minute travel time (cumulative opportunities).
The results at the state level showed that, regarding nearest opportunity, older Black people were closer to the nearest vaccination site than older whites regardless of income levels, while older Hispanics had better access than older non-Hispanic people regardless of income levels. In terms of cumulative opportunities, older Black people had more vaccination sites within 15 minutes compared to older white people, and older Hispanic people had more sites than older non-Hispanic people.
At the county level, the authors found further variation. They identified that in terms of income levels, older black people below the poverty level traveled longer and had fewer accessible vaccination sites within 15 minutes than older black people above the poverty level in Lee, Broward, and Monroe counties. Older Hispanic people below the poverty level traveled longer and had fewer opportunities than older Hispanic people above the poverty level in Gilchrist County. In addition, regarding races, older Black people traveled longer and had fewer vaccination sites than older whites in Lee and Broward counties.
Overall, the authors’ research showed that the extent of disparities in spatial accessibility may differ at the state and county levels and identified counties that need more attention from policymakers.
To read the full report, click here. To learn more about the FSU Department of Geography, visit coss.fsu.edu/geography.
APA Citation:
Kyusik Kim, Mahyar Ghorbanzadeh, Mark W. Horner & Eren Erman Ozguven (2022) Assessment of disparities in spatial accessibility to vaccination sites in Florida, Annals of GIS, 28:3, 263-277, DOI: 10.1080/19475683.2022.2026474