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Association of Zip Code Vaccination Rate With COVID-19 Mortality in Chicago, Illinois

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Key Points

Question  What was the association of vaccination coverage inequity with COVID-19 mortality in Chicago, Illinois?

Findings  In this cohort study of 2 686 355 Chicago residents, higher zip code vaccination coverage was associated with lower relative risks of death during the Alpha and Delta waves of the COVID-19 pandemic. Approximately 75% of deaths in the least vaccinated zip codes may have been prevented if mortality trends had remained parallel with the most vaccinated zip codes.

Meaning  These findings suggest that low zip code–level vaccination rates in Chicago were associated with more deaths in the Alpha and Delta waves, exacerbating racial and ethnic disparities in COVID-19 mortality.

Abstract

Importance  There has been large geographic inequity in vaccination coverage across Chicago, Illinois, with higher vaccination rates in zip codes with residents who predominantly have high incomes and are White.

Objective  To determine the association between inequitable zip code–level vaccination coverage and COVID-19 mortality in Chicago.

Design, Setting, and Participants  This retrospective cohort study used Chicago Department of Public Health vaccination and mortality data and Cook County Medical Examiner mortality data from March 1, 2020, through November 6, 2021, to assess the association of COVID-19 mortality with zip code–level vaccination rates. Data were analyzed from June 1, 2021, to April 13, 2022.

Exposures  Zip code–level first-dose vaccination rates before the Alpha and Delta waves of COVID-19.

Main Outcomes and Measures  The primary outcome was deaths from COVID-19 during the Alpha and Delta waves. The association of a marginal increase in zip code–level vaccination rate with weekly mortality rates was estimated with a mixed-effects Poisson regression model, and the total number of preventable deaths in the least vaccinated quartile of zip codes was estimated with a linear difference-in-difference design.

Results  The study population was 2 686 355 Chicago residents in 52 zip codes (median [IQR] age 34 [32-38] years; 1 378 658 [51%] women; 773 938 Hispanic residents [29%]; 783 916 non-Hispanic Black residents [29%]; 894 555 non-Hispanic White residents [33%]). Among residents in the least vaccinated quartile, 80% were non-Hispanic Black, compared with 8% of residents identifying as non-Hispanic Black in the most vaccinated quartile (P < .001). After controlling for age distribution and recovery from COVID-19, a 10–percentage point increase in zip code–level vaccination 6 weeks before the peak of the Alpha wave was associated with a 39% lower relative risk of death from COVID-19 (incidence rate ratio [IRR], 0.61 [95% CI, 0.52-0.72]). A 10–percentage point increase in zip code vaccination rate 6 weeks before the peak of the Delta wave was associated with a 24% lower relative risk of death (IRR, 0.76 [95% CI, 0.66-0.87]). The difference-in-difference estimate was that 119 Alpha wave deaths (72% [95% CI, 63%-81%]) and 108 Delta wave deaths (75% [95% CI, 66%-84%]) might have been prevented in the least vaccinated quartile of zip codes if it had had the vaccination coverage of the most vaccinated quartile.

Conclusions and Relevance  These findings suggest that low zip code–level vaccination rates in Chicago were associated with more deaths during the Alpha and Delta waves of COVID-19 and that inequitable vaccination coverage exacerbated existing racial and ethnic disparities in COVID-19 deaths.

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Article Information

Accepted for Publication: April 13, 2022.

Published: May 27, 2022. doi:10.1001/jamanetworkopen.2022.14753

Open Access: This is an open access article distributed under the terms of the CC-BY License. © 2022 Zeng S et al. JAMA Network Open.

Corresponding Author: William F. Parker, MD, PhD, Department of Medicine, University of Chicago, 5841 S Maryland Ave, MC 6076, Chicago, IL 60637 (wparker@uchicago.edu).

Author Contributions: Dr Parker had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Zeng, Pelzer, Parker.

Acquisition, analysis, or interpretation of data: Zeng, Gibbons, Peek, Parker.

Drafting of the manuscript: Zeng, Parker.

Critical revision of the manuscript for important intellectual content: Pelzer, Gibbons, Peek, Parker.

Statistical analysis: Zeng, Gibbons, Parker.

Obtained funding: Parker.

Administrative, technical, or material support: Parker.

Supervision: Gibbons, Peek, Parker.

Conflict of Interest Disclosures: Dr Peek reported receiving grants from National Institutes of Health National Heart, Lung, and Blood Institute (NHLBI) Community Engagement Alliance outside the submitted work. No other disclosures were reported.

Funding/Support: Support for this study was provided by the National Institute on Aging (grant No. 5T35AG029795-14; Ms Zeng) as part of the Pritzker Summer Research Program in Aging and the NHLBI (grant No. K08 HL150291; Dr Parker).

Role of the Funder/Sponsor: The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

References
1.
City of Chicago. COVID Dashboard. Accessed September 15, 2021. https://www.chicago.gov/city/en/sites/covid-19/home/covid-dashboard.html
2.
City of Chicago. Report date: October 27, 2020. Accessed January 29, 2022. https://www.chicago.gov/city/en/sites/covid-19/home/latest-data/2020-10-27.html
3.
Kim  SJ , Bostwick  W .  Social vulnerability and racial inequality in COVID-19 deaths in Chicago.   Health Educ Behav. 2020;47(4):509-513. doi:10.1177/1090198120929677PubMedGoogle ScholarCrossref
4.
Scannell Bryan  M , Sun  J , Jagai  J ,  et al.  Coronavirus disease 2019 (COVID-19) mortality and neighborhood characteristics in Chicago.   Ann Epidemiol. 2021;56:47-54.e5. doi:10.1016/j.annepidem.2020.10.011PubMedGoogle ScholarCrossref
5.
Hughes  MM , Wang  A , Grossman  MK ,  et al.  County-level COVID-19 vaccination coverage and social vulnerability—United States, December 14, 2020-March 1, 2021.   MMWR Morb Mortal Wkly Rep. 2021;70(12):431-436. doi:10.15585/mmwr.mm7012e1PubMedGoogle ScholarCrossref
6.
Thompson  MG , Burgess  JL , Naleway  AL ,  et al.  Interim estimates of vaccine effectiveness of BNT162b2 and mRNA-1273 COVID-19 vaccines in preventing SARS-CoV-2 infection among health care personnel, first responders, and other essential and frontline workers—eight U.S. locations, December 2020-March 2021.   MMWR Morb Mortal Wkly Rep. 2021;70(13):495-500. doi:10.15585/mmwr.mm7013e3PubMedGoogle ScholarCrossref
7.
Polack  FP , Thomas  SJ , Kitchin  N ,  et al; C4591001 Clinical Trial Group.  Safety and efficacy of the BNT162b2 mRNA COVID-19 vaccine.   N Engl J Med. 2020;383(27):2603-2615. doi:10.1056/NEJMoa2034577PubMedGoogle ScholarCrossref
8.
Baden  LR , El Sahly  HM , Essink  B ,  et al; COVE Study Group.  Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine.   N Engl J Med. 2021;384(5):403-416. doi:10.1056/NEJMoa2035389PubMedGoogle ScholarCrossref
9.
Gupta  S , Cantor  J , Simon  KI , Bento  AI , Wing  C , Whaley  CM .  Vaccinations against COVID-19 may have averted up to 140,000 deaths in the United States.   Health Aff (Millwood). 2021;40(9):1465-1472. doi:10.1377/hlthaff.2021.00619PubMedGoogle ScholarCrossref
10.
Pierce  JB , Harrington  K , McCabe  ME ,  et al.  Racial/ethnic minority and neighborhood disadvantage leads to disproportionate mortality burden and years of potential life lost due to COVID-19 in Chicago, Illinois.   Health Place. 2021;68:102540. doi:10.1016/j.healthplace.2021.102540PubMedGoogle ScholarCrossref
11.
Hunt  BR , Tran  G , Whitman  S .  Life expectancy varies in local communities in Chicago: racial and spatial disparities and correlates.   J Racial Ethn Health Disparities. 2015;2(4):425-433. doi:10.1007/s40615-015-0089-8PubMedGoogle ScholarCrossref
12.
Kershaw  KN , Robinson  WR , Gordon-Larsen  P ,  et al.  Association of changes in neighborhood-level racial residential segregation with changes in blood pressure among Black adults: the CARDIA study.   JAMA Intern Med. 2017;177(7):996-1002. doi:10.1001/jamainternmed.2017.1226PubMedGoogle ScholarCrossref
13.
Chicago Data Portal. COVID-19 cases, tests, and deaths by zip code. Accessed June 15, 2021. https://data.cityofchicago.org/Health-Human-Services/COVID-19-Cases-Tests-and-Deaths-by-ZIP-Code/yhhz-zm2v
14.
Chicago Data Portal. COVID-19 vaccination coverage by zip code—series completed. Accessed June 12, 2021. https://data.cityofchicago.org/Health-Human-Services/COVID-19-Vaccination-Coverage-by-ZIP-Code-Series-C/54sx-urja
15.
US Census Bureau. 2019: ACS 5-year estimates data profiles, DP03, selected economic characteristics: American Community Survey. Accessed August 5, 2021. https://data.census.gov/cedsci/table?g=0400000US17,17.860000_1600000US1714000&tid=ACSDP5Y2019.DP03&hidePreview=true
16.
US Census Bureau. 2019: ACS 5-year estimates data profiles, DP02, selected social characteristics: American Community Survey. Accessed August 5, 2021. https://data.census.gov/cedsci/table?g=0400000US17,17.860000_1600000US1714000&tid=ACSDP5Y2019.DP02&hidePreview=true
17.
Vasileiou  E , Simpson  CR , Shi  T ,  et al.  Interim findings from first-dose mass COVID-19 vaccination roll-out and COVID-19 hospital admissions in Scotland: a national prospective cohort study.   Lancet. 2021;397(10285):1646-1657. doi:10.1016/S0140-6736(21)00677-2PubMedGoogle ScholarCrossref
18.
City of Chicago. COVID-19 vaccine phases and rollout. Accessed August 19, 2021. https://www.chicago.gov/city/en/sites/covid19-vaccine/home/vaccine-distribution-phases.html
19.
Cook County Government. Medical examiner case archive—COVID-19 related deaths. Accessed January 19, 2022. https://datacatalog.cookcountyil.gov/Public-Safety/Medical-Examiner-Case-Archive-COVID-19-Related-Dea/3trz-enys
20.
US Department of Housing and Urban Development. HUD USPS zip code crosswalk files. Accessed January 19, 2022. https://www.huduser.gov/portal/datasets/usps_crosswalk.html
21.
Chicago vaccine allocation. Accessed April 22. 2022. https://github.com/zengsharon/ChicagoVaccineAllocation
22.
Bilal  U , Tabb  LP , Barber  S , Diez Roux  AV .  Spatial inequities in COVID-19 testing, positivity, confirmed cases, and mortality in 3 U.S. cities: an ecological study.   Ann Intern Med. 2021;174(7):936-944. doi:10.7326/M20-3936PubMedGoogle ScholarCrossref
23.
Mustanski  B , Saber  R , Ryan  DT ,  et al.  Geographic disparities in COVID-19 case rates are not reflected in seropositivity rates using a neighborhood survey in Chicago.   Ann Epidemiol. 2022;66:44-51. doi:10.1016/j.annepidem.2021.10.006PubMedGoogle ScholarCrossref
24.
Tung  EL , Peek  ME , Rivas  MA , Yang  JP , Volerman  A .  Association of neighborhood disadvantage with racial disparities in COVID-19 positivity in Chicago.   Health Aff (Millwood). 2021;40(11):1784-1791. doi:10.1377/hlthaff.2021.00695PubMedGoogle ScholarCrossref
25.
Krumholz  HM , Normand  SLT , Keenan  PS ,  et al. Hospital 30-day AMI readmission measure methodology. Accessed June 28, 2021. https://qualitynet.cms.gov/files/5d0d375b764be766b0101427?filename=AMI_ReadmMeasMethod.pdf
26.
Vevea  B , Schorsch  K . How one Chicago zip code got 500 times more vaccine doses than another. WBEZ Chicago. March 31, 2021. Accessed August 18, 2021. https://www.wbez.org/stories/vaccine-shipments-in-chicago/8cbeb170-53e0-40a6-96ea-68d26949f6c7
27.
Waltenburg  MA , Rose  CE , Victoroff  T ,  et al; CDC COVID-Emergency Response Team.  Coronavirus disease among workers in food processing, food manufacturing, and agriculture workplaces.   Emerg Infect Dis. 2021;27(1):243-249. doi:10.3201/eid2701.203821PubMedGoogle ScholarCrossref
28.
Schorsch  K . Chinatown found its own solution for bringing vaccines closer to home. WBEZ Chicago. April 28, 2021. Accessed August 18, 2021. https://www.wbez.org/stories/why-chinatown-created-its-own-covid-19-vaccination-sites/3c8ef267-2af8-418c-8519-9edd36002752
29.
Vevea  B , Schorsch  K . Chicago’s plan to flood areas with COVID-19 vaccines improved racial equity—now it’s ending. WBEZ Chicago. May 19, 2021. Accessed June 11, 2021. https://www.wbez.org/stories/chicagos-plan-to-flood-areas-with-covid-19-vaccines-improved-racial-equity-now-its-ending/356d0aeb-43a2-4b2f-a6c9-1c6a2b49884b
30.
Alfieri  NL , Kusma  JD , Heard-Garris  N ,  et al.  Parental COVID-19 vaccine hesitancy for children: vulnerability in an urban hotspot.   BMC Public Health. 2021;21(1):1662. doi:10.1186/s12889-021-11725-5PubMedGoogle ScholarCrossref
31.
Toth-Manikowski  SM , Swirsky  ES , Gandhi  R , Piscitello  G .  COVID-19 vaccination hesitancy among health care workers, communication, and policy-making.   Am J Infect Control. 2022;50(1):20-25. doi:10.1016/j.ajic.2021.10.004PubMedGoogle ScholarCrossref
32.
Bogart  LM , Ojikutu  BO , Tyagi  K ,  et al.  COVID-19 related medical mistrust, health impacts, and potential vaccine hesitancy among Black Americans living with HIV.   J Acquir Immune Defic Syndr. 2021;86(2):200-207. doi:10.1097/QAI.0000000000002570PubMedGoogle ScholarCrossref
33.
Thompson  HS , Manning  M , Mitchell  J ,  et al.  Factors associated with racial/ethnic group-based medical mistrust and perspectives on COVID-19 vaccine trial participation and vaccine uptake in the US.   JAMA Netw Open. 2021;4(5):e2111629. doi:10.1001/jamanetworkopen.2021.11629PubMedGoogle ScholarCrossref
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