Social Vulnerability, Disadvantage, and COVID-19 Vaccine Rationing: A Review Characterizing the Construction of Disadvantage Indices Deployed To Promote Equitable Allocation of Resources in the United States

When planners began developing COVID-19 vaccine rationing frameworks in 2020, an additional major challenge arose, as the spread of the virus was exacerbated by major health disparities. In an unprecedented, novel turn, planners added statistical place-based measures of deprivation, known as disadvantage indices, to traditional sequential allocation frameworks. To better understand the construction of these indices and their role in equitable allocation, we reviewed the most commonly used indices with publicly available documentation.We characterized four indices: Area Deprivation Index (ADI), COVID-19 Community Vulnerability Index (CCVI), Healthy Places Index (HPI), and Social Vulnerability Index (SVI).Seventy-eight total variables from the following nine domains were used to construct these indices: population demographics, poverty, education and employment, minority populations, housing, and transportation, high-risk transmission environments, health, healthcare system, and environmental and neighborhood.Geographic units that the indices were applied to range from the block group to census tract, zip code, and county level. U.S. Census Bureau’s American Community Survey was the primary source of data, but indices varied greatly on variables and geography used, weighting schemes, and reporting units.While all indices have comparable goals, their designs differed considerably. Given the clear potential to promote equity in the pandemic setting and, plausibly, outside of it, further analyses should systematically elicit the tradeoffs associated with using different types of indices.