Experiences of Sex Workers in Chicago during COVID-19: A Qualitative Study.

COVID-19 exacerbated health disparities, financial insecurity, and occupational safety for many within marginalized populations. This study, which took place between 2019 and 2022, aimed to explore the way in which sex workers (n = 36) in Chicago were impacted by COVID-19. We analyzed the transcripts of 36 individual interviews with a diverse group of sex workers using thematic analysis. Five general themes emerged regarding the detrimental impact of COVID-19 on sex workers: (1) the impact of COVID-19 on physical health; (2) the economic impact of COVID-19; (3) the impact of COVID-19 on safety; (4) the impact of COVID-19 on mental health; and (5) adaptive strategies for working during COVID-19. Participants reported that their physical and mental health, economic stability, and safety worsened due to COVID-19 and that adaptive strategies did not serve to improve working conditions. Findings highlight the ways in which sex workers are particularly vulnerable during a public health crisis, such as COVID-19. In response to these findings, targeted resources, an increased access to funding, community-empowered interventions and policy changes are needed to protect the health and safety of sex workers in Chicago.

Lessons (Not) Learned: Chicago Death Inequities during the 1918 Influenza and COVID-19 Pandemics.

During historical and contemporary crises in the U.S., Blacks and other marginalized groups experience an increased risk for adverse health, social, and economic outcomes. These outcomes are driven by structural factors, such as poverty, racial residential segregation, and racial discrimination. These factors affect communities' exposure to risk and ability to recover from disasters, such as pandemics. This study examines whether areas where descendants of enslaved Africans and other Blacks lived in Chicago were vulnerable to excess death during the 1918 influenza pandemic and whether these disparities persisted in the same areas during the COVID-19 pandemic. To examine disparities, demographic data and influenza and pneumonia deaths were digitized from historic weekly paper maps from the week ending on 5 October 1918 to the week ending on 16 November 1918. Census tracts were labeled predominantly Black or white if the population threshold for the group in a census tract was 40% or higher for only one group. Historic neighborhood boundaries were used to aggregate census tract data. The 1918 spatial distribution of influenza and pneumonia mortality rates and cases in Chicago was then compared to the spatial distribution of COVID-19 mortality rates and cases using publicly available datasets. The results show that during the 1918 pandemic, mortality rates in white, immigrant and Black neighborhoods near industrial areas were highest. Pneumonia mortality rates in both Black and immigrant white neighborhoods near industrial areas were approximately double the rates of neighborhoods with predominantly US-born whites. Pneumonia mortality in Black and immigrant white neighborhoods, far away from industrial areas, was also higher (40% more) than in US-born white neighborhoods. Around 100 years later, COVID-19 mortality was high in areas with high concentrations of Blacks based on zip code analysis, even though the proportion of the Black population with COVID was similar or lower than other racial and immigrant groups. These findings highlight the continued cost of racial disparities in American society in the form of avoidable high rates of Black death during pandemics.

Chicago's Citywide COVID-19 Vaccine Equity Program: Protect Chicago Plus.

Vaccination is one of the most effective strategies to control the spread of COVID-19 and reduce morbidity and mortality; however, rapid and equitable vaccine distribution is required to achieve such outcomes. We conducted a basic interrupted time-series analysis to examine the short-term impacts of a citywide vaccine equity plan, the Protect Chicago Plus (PCP) plan. We compared vaccine coverage in zip codes in Chicago with high COVID-19 vulnerability, as identified from the Chicago COVID-19 Community Vulnerability Index, with coverage in all other zip codes in Chicago. From our analysis, we observed that implementation of PCP coincided with reduced vaccination disparities between Chicago communities with low and high vulnerability indexes over time. In our analysis of vaccination coverage before program implementation, vaccination coverage climbed nearly twice as fast among non-PCP zip codes (0.19% per day) than among PCP zip codes (0.10% per day) or by 0.09 percentage points (P < .001). In model analysis after program implementation, zip codes prioritized for the program had 0.42% additional coverage per day as compared with 0.27% per day for non-PCP zip codes. Our findings suggest that such programs may improve vaccine equity, but additional research is needed to better understand the longer-term effects of citywide vaccination strategies on vaccine uptake.

The mediating effect of health literacy on COVID-19 vaccine confidence among a diverse sample of urban adults in Boston and Chicago.

BACKGROUND: A high rate of COVID-19 vaccination is critical to reduce morbidity and mortality related to infection and to control the COVID-19 pandemic. Understanding the factors that influence vaccine confidence can inform policies and programs aimed at vaccine promotion. We examined the impact of health literacy on COVID-19 vaccine confidence among a diverse sample of adults living in two major metropolitan areas. METHODS: Questionnaire data from adults participating in an observational study conducted in Boston and Chicago from September 2018 through March 2021 were examined using path analyses to determine whether health literacy mediates the relationship between demographic variables and vaccine confidence, as measured by an adapted Vaccine Confidence Index (aVCI). RESULTS: Participants (N = 273) were on average 49 years old, 63 % female, 4 % non-Hispanic Asian, 25 % Hispanic, 30 % non-Hispanic white, and 40 % non-Hispanic Black. Using non-Hispanic white and other race as the reference category, Black race and Hispanic ethnicity were associated with lower aVCI (-0.76, 95 % CI -1.00 to -0.50; -0.52, 95 % CI -0.80 to -0.27, total effects from a model excluding other covariates). Lower education was also associated with lower aVCI (using college or more as the reference, -0.73 for 12th grade or less, 95 % CI -0.93 to -0.47; -0.73 for some college/associate's/technical degree, 95 % CI -1.05 to -0.39). Health literacy partially mediated these effects for Black and Hispanic participants and those with lower education (indirect effects -0.19 and -0.19 for Black race and Hispanic ethnicity; 0.27 for 12th grade or less; -0.15 for some college/associate's/technical degree). CONCLUSIONS: Lower levels of education, Black race, and Hispanic ethnicity were associated with lower scores on health literacy, which in turn were associated with lower vaccine confidence. Our findings suggest that efforts to improve health literacy may improve vaccine confidence, which in turn may improve vaccination rates and vaccine equity. CLINICAL TRIALS NUMBER: NCT03584490.

Polysubstance use in a community sample of Black cisgender sexual minority men and transgender women in Chicago during initial COVID-19 pandemic peak.

BACKGROUND: In response to COVID-19, the city of Chicago issued stay-at-home orders, which began on March 20, 2020, and restrictions meant to "flatten the curve" remained in effect until June 2, 2020. On June 3, 2020, Chicago entered the reopening phase. This study compares rates of polysubstance use by COVID-19 lockdown phase and across sociodemographic characteristics in a Chicago-based sample of Black cisgender sexual minority men (SMM) and transgender women. METHOD: Data come from the Neighborhood and Networks (N2) cohort, an ongoing study of Black cisgender SMM and transgender women living in Chicago. Participants (N = 226) completed a survey between April 20, 2020, and July 30, 2020, during the initial peak of the COVID-19 pandemic in Chicago. We conducted chi-square tests of independence and modified Poisson regression models with robust error variance and estimated adjusted prevalence ratios. RESULTS: Alcohol and marijuana were the most used substances, with 73.5% reporting at least one drinking day and 71.2% of the sample reporting marijuana use in the past 14 days. Tobacco was used by 41.6% of the sample, and illegal drug use, which does not include marijuana, was reported by 17.7% of the sample. Substance use was consistently associated with the use of other substances. As such, polysubstance use (i.e., using two or more substances) was common in this sample (63.7%). Few sociodemographic differences emerged, and substance use was not associated with lockdown phase. CONCLUSION: Substance use, including polysubstance use, was high in our sample of Black SMM and transgender women during the initial peak of the COVID-19 pandemic. Continued monitoring is needed given the duration of the COVID-19 pandemic and the negative health consequences associated with substance use in this population.

COVID-19 Clusters and Outbreaks Among Non-Health Care, Noncongregate Workers in Chicago, Illinois: Surveillance Through the First Omicron Wave.

OBJECTIVE: To describe COVID-19 investigations by a large urban health department among non-health care, noncongregate workplaces and the utility of surveillance methods over time. METHODS: Frequencies of workplace-associated clusters and outbreaks are described by workplace type, workforce size, and method of identification over time. RESULTS: From April 2020 through January 2022, 496 COVID-19 investigations identified 442 clusters (89%) and 54 outbreaks (11%). Frontline essential workplaces comprised 36% of investigations before versus 15% after vaccine eligibility. Pre-Omicron, most investigations (84%) were identified through case interviews. During Omicron predominance, case interviews decreased dramatically and identified 10% of investigations. Offices (41%) and bars and restaurants (36%) were overrepresented, and only one outbreak was identified, given decreases in confirmatory testing. CONCLUSIONS: Findings suggest that vaccine prioritization reduced COVID-19 burden among highest-risk workplaces, but surveillance methods likely became less representative over time.

Assessing widening disparities in HbA1c and systolic blood pressure retesting during the COVID-19 pandemic in an LGBTQ+-focused federally qualified health center in Chicago: a retrospective cohort study using electronic health records.

INTRODUCTION: To assess disparities in retesting for glycated hemoglobin (HbA1c) and systolic blood pressure (SBP) among people with diabetes mellitus (DM) and hypertension (HTN), respectively, we analyzed medical records from a lesbian, gay, bisexual, transgender, queer-specialized federally qualified health center with multiple sites in Chicago. RESEARCH DESIGN AND METHODS: We identified people with DM seen in 2018 and 2019 then assessed if individuals had HbA1c retested the following year (2019 and 2020). We repeated this using SBP for people with HTN. Rates of retesting were compared across gender, sexual orientation, and race and ethnicity and across the 2 years for each categorization with adjustment for socioeconomic indicators. RESULTS: Retesting rates declined from 2019 to 2020 for both HbA1c and SBP overall and across all groups. Cisgender women and transgender men with DM (vs cisgender men) and straight people (vs gay men) had significantly lower odds of HbA1c retesting for both years. There was evidence of widening of HbA1c retesting disparities in 2020 between gay men and other orientations. Cisgender women, straight people, and black people (vs white) with HTN had significantly lower odds of SBP retesting for both years. There was evidence of narrowing in the retesting gap between black and white people with HTN, but this was due to disproportionate increase in no retesting in white people rather than a decline in no retesting among black people with HTN. CONCLUSIONS: Disparities in DM and HTN care according to gender, race, ethnicity, and sexual orientation persisted during the pandemic with significant widening according to sexual orientation.

Unified Response to COVID-19 Case Investigation and Contact Tracing, Chicago, December 2020-April 2021.

OBJECTIVES: We evaluated 2 innovative approaches that supported COVID-19 case investigation and contact tracing (CI/CT) in Chicago communities: (1) early engagement of people diagnosed with COVID-19 by leveraging the existing Healthcare Alert Network to send automated telephone calls and text messages and (2) establishment of a network of on-site case investigators and contact tracers within partner health care facilities (HCFs) and community-based organizations (CBOs). METHODS: The Chicago Department of Public Health used Healthcare Alert Network data to calculate the proportion of people with confirmed COVID-19 who successfully received an automated telephone call or text message during December 27, 2020-April 24, 2021. The department also used CI/CT data to calculate the proportion of cases successfully interviewed and named contacts successfully notified, as well as the time to successful case interview and to successful contact notification. RESULTS: Of 67 882 people with COVID-19, 94.3% (n = 64 011) received an automated telephone call and 91.7% (n = 62 239) received a text message. Of the 65 470 COVID-19 cases pulled from CI/CT data, 24 450 (37.3%) interviews were completed, including 6212 (61.3%) of the 10 126 cases diagnosed in HCFs. The median time from testing to successful case interview was 3 days for Chicago Department of Public Health investigators and 4 days for HCF investigators. Overall, 34 083 contacts were named; 13 117 (38.5%) were successfully notified, including 9068 (36.6%) of the 24 761 contacts assigned to CBOs. The median time from contact elicitation to completed notification by CBOs was <24 hours. CONCLUSIONS: Partnerships with HCFs and CBOs helped deliver timely CI/CT during the COVID-19 pandemic, suggesting a potential benefit of engaging non-public health institutions in CI/CT for existing and emerging diseases.

The impact of COVID-19 pandemic on ridesourcing services differed between small towns and large cities.

To curb the spread of the ongoing 2019 novel coronavirus (COVID-19), authorities have adopted several non-pharmaceutical (NPIs) and pharmaceutical interventions, which significantly affected our daily activities and mobility patterns. However, it is still unclear how severity of NPIs, COVID-19-related variables, and vaccination rates have affected demand for ridesourcing services, and whether these effects vary across small towns and large cities. We analyzed over 220 million ride requests in the City of Chicago (population: 2.7 million), Illinois, and 52 thousand in the Town of Innisfil (population: 37 thousand), Ontario, to investigate the impact of the COVID-19 pandemic on the ridesourcing demand in the two locations. Overall, the pandemic resulted in fewer trips in areas with higher proportions of seniors and more trips to parks and green spaces. Ridesourcing demand was adversely affected by the stringency index and COVID-19-related variables, and positively affected by vaccination rates. However, compared to Innisfil, ridesourcing services in Chicago experienced higher reductions in demand, were more affected by the number of hospitalizations and deaths, were less impacted by vaccination rates, and had lower recovery rates.

Tracking changes in SARS-CoV-2 transmission with a novel outpatient sentinel surveillance system in Chicago, USA.

Public health indicators typically used for COVID-19 surveillance can be biased or lag changing community transmission patterns. In this study, we investigate whether sentinel surveillance of recently symptomatic individuals receiving outpatient diagnostic testing for SARS-CoV-2 could accurately assess the instantaneous reproductive number R(t) and provide early warning of changes in transmission. We use data from community-based diagnostic testing sites in the United States city of Chicago. Patients tested at community-based diagnostic testing sites between September 2020 and June 2021, and reporting symptom onset within four days preceding their test, formed the sentinel population. R(t) calculated from sentinel cases agreed well with R(t) from other indicators. Retrospectively, trends in sentinel cases did not precede trends in COVID-19 hospital admissions by any identifiable lead time. In deployment, sentinel surveillance held an operational recency advantage of nine days over hospital admissions. The promising performance of opportunistic sentinel surveillance suggests that deliberately designed outpatient sentinel surveillance would provide robust early warning of increasing transmission.

Patient Income Does Not Predict Disability or Mortality in Hospitalized COVID-19 Patients in a Large Health Care System in the Chicago Metropolitan Area.

Race, income, and their role in COVID-19 infection in the community have been extensively reported, but their impact on outcomes in hospitalized patients is less well defined. We retrospectively analyzed the first 509 COVID-19 patients in our hospital network, examining associations between median household income, 30-day mortality, and ambulatory state at discharge (using the modified Rankin scale (mRS)), adjusting for hospitalization at the academic medical center (AMC) and other variables. Income did not predict mortality. Higher income was associated with slightly increased odds of ability to ambulate at discharge only when accounting for hospital type. At the AMC, income and mortality were lower and functional outcomes more favorable. Patients with lower incomes had greater comorbidity burden. That income was not associated with measures of morbidity and mortality from COVID-19 is a remarkable and encouraging finding. Academic medical centers may mitigate detrimental effects of socioeconomic disparities on COVID-19 seen at the community level.

"Even if I'm undetectable, I just feel like I would die": a qualitative study to understand the psychological and socioeconomic impacts of the COVID-19 pandemic on women living with HIV (WLWH) in Chicago, IL.

BACKGROUND: The COVID-19 pandemic has affected the health and well-being of people worldwide, yet few studies have qualitatively examined its cumulative effects on ciswomen living with HIV (WLWH). We aimed to explore how the pandemic has impacted WLWH, including challenges related to HIV care, employment, finances, and childcare. We also investigated how HIV status and different psychosocial stressors affected their mental health. METHODS: We performed 25 semi-structured qualitative interviews with WLWH regarding the ways in which COVID-19 impacted their social determinants of health and physical well-being during the pandemic. 19 WLWH who received care at the University of Chicago Medicine (UCM) and 6 women who received care at Howard Brown Health, a federally qualified health center (FQHC) in Chicago, were interviewed remotely from June 2020 to April 2021. All interviews were audio recorded and transcribed. Interviews were thematically analyzed for commonalities regarding HIV-specific and general experiences of WLWH during the pandemic. RESULTS: The majority of participants reported COVID-19 impacted their HIV care, such as appointment cancellations and difficulties adhering to antiretroviral therapy. In addition to HIV care obstacles, almost all participants described perceived heightened vulnerability to or fear of COVID-19. The pandemic also affected the socioeconomic well-being of participants, with reported financial strains and employment disruptions. Some mothers took on additional childcare responsibilities, such as homeschooling. Increased mental health concerns and negative psychological effects from the social isolation associated with the pandemic were also experienced by most participants. CONCLUSIONS: We gained invaluable insight into how WLWH were challenged by and adapted to the COVID-19 pandemic, including its destabilizing effects on their HIV care and mental health. Women described how they undertook additional childcare responsibilities during the pandemic and how their HIV status compounded their concerns (e.g., perceived heightened vulnerability to COVID-19). Strategies to better support WLWH in maintaining their overall health throughout the pandemic include childcare assistance, access to affordable mental health services, support groups, and education from HIV care providers. These findings have significant implications for examining future health crises through the perspective of potential gender inequalities.

Supporting Retention in HIV Care: Comparing In-Person and Telehealth Visits in a Chicago-Based Infectious Disease Clinic.

The COVID-19 pandemic has created increased need for telehealth appointments. To assess differences in appointment adherence for telehealth compared to in-person HIV medical care visits, we conducted a cross-sectional study of patients receiving HIV care in a safety-net hospital-based outpatient infectious disease clinic in a large urban area (Chicago, IL). The sample (N = 347) was predominantly Black (n = 251) and male (62.5%, n = 217); with a mean age of 44.2 years. Appointment attendance was higher for telehealth (78.9%) compared to in-person (61.9%) appointments. Compared to patients without drug use, those with drug use had 19.4 percentage point lower in-person appointment attendance. Compared to those with stable housing, those in unstable housing arrangements had 15.0 percentage point lower in-person appointment attendance. Telehealth as a modality will likely have some staying power as it offers patients newfound flexibility, but barriers to telehealth need to be assessed and addressed.

Impact of COVID-19 on the mobility patterns: An investigation of taxi trips in Chicago.

The COVID-19 outbreak has impacted urban transportation mobility throughout the world. In this paper, we investigate the impact of COVID-19 on the urban mobility network's structural characteristics. We contribute to the literature by discussing how various community areas in the city traffic network are impacted by the pandemic. We analyze a large dataset on urban mobility from the city of Chicago and derive various insights. Our analysis of the mobility network structure is important because a better understanding of such networks can help control the spread of the disease by reducing interactions among individuals. We find that the pandemic significantly impacted the structure of the mobility network of taxis in Chicago. Our study reveals some important pointers for policymakers that could potentially aid in developing urban transportation policies during the pandemic.

Positivity rates of SAR-CoV-2 infection in orthodontic patients at the orthodontic clinic, University of Illinois Chicago.

COVID-19 has impacted and increased risks for healthcare providers, including orthodontists. There is no information regarding the potential transmission risks in the orthodontic community. This study aims to compare the positivity rate of SARS-CoV-2 infection in orthodontic patients at the University of Illinois Chicago (UIC) orthodontic clinic to the positivity rate of the local population in Chicago. All orthodontic patients who sought treatment at the UIC orthodontic clinic from June 16 to October 31, 2021, were invited to participate in the study. Three milliliters of saliva from the participants were collected in the sample collection tubes and subjected to a polymerase chain reaction (PCR) based assay to detect SAR-CoV-2. All participants' age, sex, history of COVID-19 infection, and vaccination status were recorded. The COVID-19 positivity rates of Chicago, Cook County of Illinois, and the orthodontic clinic at UIC were compared. One thousand four hundred and thirty-seven orthodontic patients aged 6 to 70 years old (41.8% males and 58.2% females) participated in the study. Among all participants, nine participants tested positive for SARS-CoV-2 (5 males and 4 females). During the study, the average COVID-19 positivity rate at the UIC orthodontic clinic was 0.626%. All of the positive participants were asymptomatic, and two of the participants had a history of COVID-19 infection. Among all positive participants, three participants had received complete COVID-19 vaccination. An increased frequency of positive cases at the orthodontic clinic was observed during the time of high positivity rate in Chicago and Cook County. A potential risk of COVID-19 transmission from patients to orthodontic providers remains, even with asymptomatic and vaccinated patients.

COVID-19 Conspiracy Beliefs are not Barriers to HIV Status Neutral Care Among Black Cisgender Sexual Minority Men and Black Transgender Women at the Initial Peak of the COVID-19 Pandemic in Chicago, USA.

We examined associations between COVID-19 conspiracy beliefs and HIV status neutral care engagement among Black cisgender sexual minority men (BCSMM) and Black transgender women (BTW). Throughout April-July 2020, a total of 226 (222 in the current analysis: 196 BCSMM, 20 BTW, and 6 other) participants in Chicago's Neighborhoods and Networks (N2) cohort study completed virtual assessments. Participants reported their HIV status, changes in the frequency of PrEP/ART use, and COVID-19 conspiracy beliefs. Three-quarters of the sample believed at least one conspiracy theory that COVID-19 was either government-created or lab-created accidentally or purposefully. Believing one or more COVID-19 conspiracy theories was significantly associated with better PrEP or ART engagement (using PrEP more frequently or continuously using PrEP/Missing ART less or continuously using ART) (aPR = 0.75 [95% CI 0.56-0.99], p < 0.05). Believing COVID-19 came about naturally was strongly associated with worse PrEP engagement (i.e., use PrEP less or not on PrEP) or worse ART engagement (i.e., missed ART more or not on ART) (aPR = 1.56 [95% CI 1.23, 1.98], p < 0.001). Findings suggested substantial COVID-19 conspiracies among BCSMM and BTW, and this was associated with HIV care engagement.

Impact of changes in protective behaviors and out-of-household activities by age on COVID-19 transmission and hospitalization in Chicago, Illinois.

PURPOSE: Even with an efficacious vaccine, protective behaviors (social distancing, masking) are essential for preventing COVID-19 transmission and could become even more important if current or future variants evade immunity from vaccines or prior infection. METHODS: We created an agent-based model representing the Chicago population and conducted experiments to determine the effects of varying adult out-of-household activities (OOHA), school reopening, and protective behaviors across age groups on COVID-19 transmission and hospitalizations. RESULTS: From September-November 2020, decreasing adult protective behaviors and increasing adult OOHA both substantially impacted COVID-19 outcomes; school reopening had relatively little impact when adult protective behaviors and OOHA were maintained. As of November 1, 2020, a 50% reduction in young adult (age 18-40) protective behaviors resulted in increased latent infection prevalence per 100,000 from 15.93 (IQR 6.18, 36.23) to 40.06 (IQR 14.65, 85.21) and 19.87 (IQR 6.83, 46.83) to 47.74 (IQR 18.89, 118.77) with 15% and 45% school reopening. Increasing adult (age ≥18) OOHA from 65% to 80% of prepandemic levels resulted in increased latent infection prevalence per 100,000 from 35.18 (IQR 13.59, 75.00) to 69.84 (IQR 33.27, 145.89) and 38.17 (IQR 15.84, 91.16) to 80.02 (IQR 30.91, 186.63) with 15% and 45% school reopening. Similar patterns were observed for hospitalizations. CONCLUSIONS: In areas without widespread vaccination coverage, interventions to maintain adherence to protective behaviors, particularly among younger adults and in out-of-household settings, remain a priority for preventing COVID-19 transmission.

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

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.

Multistate Outbreak of Infection with SARS-CoV-2 Omicron Variant after Event in Chicago, Illinois, USA, 2021.

Bars and restaurants are high-risk settings for SARS-CoV-2 transmission. A multistate outbreak after a bar gathering in Chicago, Illinois, USA, highlights Omicron variant transmissibility, the value of local genomic surveillance and interstate coordination, vaccination value, and the potential for rapid transmission of a novel variant across multiple states after 1 event.