Social inequalities and the early provision and dispersal of COVID-19 vaccinations in the United States: A population trends study

Background: In December 2020 the U.S. began a massive COVID-19 vaccination campaign, an action that researchers felt could catalyze inequalities in COVID-19 vaccination utilization. While vaccines have the potential to be accessible regardless of social status, the objective of this study was to examine how and when socioeconomic status (SES) and racial/ethnic inequalities would emerge in vaccination distribution.

Methods: Population vaccination rates reported at the county level by the Centers for Disease Control and Prevention across 46 states on 3/30/2021. Correlates included SES, the share of the population who were Black, Hispanic, Female, or aged ≥65 years, and urbanicity (thousands of residents per square mile). Multivariable-adjusted analyses relied on zero-inflated negative binomial regression to estimate the odds of providing any vaccine, and vaccination rate ratios (aVRR) comparing the distribution rate for vaccinations across the U.S.

Results: Across the U.S., 16.3 % of adults and 37.9 % of adults aged 65 and older were vaccinated in lower SES counties, while 20.45 % of all adults and 48.15 % of adults aged 65 and older were vaccinated in higher SES counties. Inequalities emerged after 41 days, when < 2 % of Americans were vaccinated. Multivariable-adjusted analyses revealed that higher SES was associated with improved vaccination distribution (aVRR = 1.127, [1.100-1.155], p < 1E-06), while increases in the percent reporting Black or Hispanic race/ethnicity was associated with lower vaccination distribution (aVRR = 0.998, [0.996-0.999], p = 1.03E-04).

Conclusions: Social inequalities in COVID-19 vaccines reflect an inefficient and inequitable distribution of these technologies. Future efforts to improve health should recognize the central role of social factors in impacting vaccine delivery.