Pritzker Student Research Showing Vaccine Inequities in Spotlight

Pritzker MS2’s research on vaccine allocation in Chicago prompts deep dive from WBEZ

New research findings published as a pre-print co-authored by a Pritzker School of Medicine student showing COVID-19 vaccine disparities in the city of Chicago are in the spotlight following a closer look from local NPR affiliate WBEZ.

Second-year Pritzker student Sharon Zeng served as first-author on the paper “Consequences of COVID-19 vaccine allocation inequity in Chicago,” which found inequity in the city’s strategy led to unnecessary deaths in some of the city’s most vulnerable communities. Zeng was funded by an NIA T35 grant and initiated the project as part of Pritzker’s Summer Research Program.

The manuscript, which is under peer review, caught WBEZ’s attention, and the outlet did a deep dive on the data in conjunction with Documenting COVID-19, a journalism collaborative, and MuckRock, a non-profit organization focused on government transparency. The reporting team’s review of the UChicago study, interviews with public health experts, and additional data concluded that “despite the city’s efforts to improve vaccine equity, the initial phase of Protect Chicago Plus did not prioritize some vulnerable communities.”

The study out of the University of Chicago Healthcare Ethics and Allocation Lab (HEAL) at the MacClean Center for Clinical Medical Ethics examined the association between ZIP-code level vaccination rate and COVID-19 mortality in residents of 52 ZIP codes in Chicago. Dr. William Parker of the UChicago Department of Medicine Section of Pulmonary/Critical Care and Assistant Director of the MacClean Center led the research team. A Pritzker alumnus himself (’12), Parker served as Zeng’s project mentor.

The analysis found the city “could have prevented an estimated 72% of deaths in the least vaccinated quartile of the city if it had had the same vaccination rate as the most vaccinated quartile” through March 28, 2021 and concluded “Inequitable vaccine allocation in Chicago likely exacerbated existing racial disparities in COVID-19 mortality.” In simple terms, the study suggested more equitable vaccine distribution could have save 118 lives in the Spring of 2021, accounting for the difference between deaths in the two quartiles.

In response to WBEZ’s conclusion, the Commissioner of the Chicago Department of Public Health Dr. Allison Arwady maintained that the city distributed vaccines as equitably as possible at a time when supply was low.

“Everything we did was to try to decrease that inequity,” Arwady told WBEZ.

The Protect Chicago Plus plan utilized a COVID-19 Community Vulnerability Index to rank all 77 Chicago community areas for risk related to the virus. The measure placed 24 community areas in the “high” category, and the top 15 highest-risk areas were prioritized for extra doses of the vaccine in late winter of 2020 and spring of 2021. While vaccine hesitancy likely played a part in low vaccination rates for highly vulnerable ZIP codes, the new study pointed to additional inequities.

The UChicago study found that by April 2021 the least vaccinated ZIP codes in Chicago were primarily on the city’s South and West sides. This, Parker told WBEZ, was partially the result of the city not sending more doses to hospitals serving only disadvantaged communities. 

“Places like St. Bernard Hospital in Englewood should have just had as many doses as they could administer,” Parker said. “That wasn’t the case.”

Despite the city’s attempts to prioritize vulnerable communities in its vaccine distribution, the study determined “the city disproportionately allocated vaccines to zip codes with high incomes and predominantly White populations.”