Contribution of vaccinations to reducing socioeconomic disparities in COVID-19 deaths across U.S. counties

Purpose: Although increasing vaccine uptake is a key strategy to minimize Coronavirus Disease 2019 (COVID-19) deaths, evidence of the role of vaccination rates in attenuating the socioeconomic disparity in COVID-19 deaths is limited. We thus aimed to quantify the extent to which vaccination rates contribute to the association between U.S. county-level poverty rates and COVID-19 mortality rates.

Methods: This nationwide study analyzed data on 3142 U.S. counties. We conducted mediation analyses to calculate the proportions eliminated (PE) of the association between poverty rate and COVID-19 deaths per 100,000 population by setting the COVID-19 vaccination rate (the proportion of fully vaccinated individuals as of December 31, 2021) to different observed values.

Results: Adjusted for county-level characteristics, we estimate an additional 25.3 COVID-19 deaths per 100,000 population for each 10% increase in a county's poverty rate. When we set the vaccination rate at its maximum, 90th percentile, and 75th percentile of the observed values, the PE was estimated to be 81% (P < .001), 37% (P < .001), and 21% (P < .001), respectively.

Conclusions: Higher county-level poverty rates and lower vaccination rates were associated with greater COVID-19 mortality rates in the United States. Aggressive interventions to increase vaccine uptake could substantially reduce the social disparity in COVID-19 mortality.