Neighborhood-level COVID vaccination and booster disparities: A population-level analysis across California

Debora L Oh; Kathryn E Kemper; Dan Meltzer; Alison J Canchola; Kirsten Bibbins-Domingo; Courtney R Lyles

doi:10.1016/j.ssmph.2023.101366

Neighborhood-level COVID vaccination and booster disparities: A population-level analysis across California

SSM Popul Health. 2023 Feb 21:22:101366. doi: 10.1016/j.ssmph.2023.101366. eCollection 2023 Jun.

Authors

Debora L Oh¹, Kathryn E Kemper^{1

2}, Dan Meltzer¹, Alison J Canchola¹, Kirsten Bibbins-Domingo^{1

2

3}, Courtney R Lyles^{1

2

3}

Affiliations

¹ Department of Epidemiology & Biostatistics, University of California San Francisco, 550 16th Street, 2nd Floor, San Francisco, CA, 94158, United States.
² UCSF Center for Vulnerable Populations, Zuckerberg San Francisco General Hospital, 2789 25th Street, Suite 350, San Francisco, CA, 94143, United States.
³ Department of Medicine, Division of General Internal Medicine at Zuckerberg San Francisco General Hospital, University of California San Francisco, 1001 Portrero Avenue, Bldg 10, San Francisco, CA, 94110, United States.

Abstract

Objectives: To describe vaccine and booster uptake by neighborhood-level factors in California.

Methods: We examined trends in COVID-19 vaccination up to September 21, 2021, and boosters up to March 29, 2022 using data from the California Department of Public Health. Quasi-Poisson regression was used to model the association between neighborhood-level factors and fully vaccinated and boosted among ZIP codes. Sub-analyses on booster rates were compared among the 10 census regions.

Results: In a minimally adjusted model, a higher proportion of Black residents was associated with lower vaccination (HR = 0.97; 95%CI: 0.96-0.98). However, in a fully adjusted model, proportion of Black, Hispanic/Latinx, and Asian residents were associated with higher vaccination rates (HR = 1.02; 95%CI: 1.01-1.03 for all). The strongest predictor of low vaccine coverage was disability (HR = 0.89; 95%CI: 0.86-0.91). Similar trends persisted for booster doses. Factors associated with booster coverage varied by region.

Conclusions: Examining neighborhood-level factors associated with COVID-19 vaccination and booster rates uncovered significant variation within the large and geographically and demographically diverse state of California. Equity-based approaches to vaccination must ensure a robust consideration of multiple social determinants of health.

Keywords: ACS, American Community Survey; CDPH, California Department of Public Health; COVID-19; COVID-19, Coronavirus Disease 2019; Health disparities; LEP, Limited English Proficiency; Neighborhood; Population health; SDOH, Social Determinants of Health; Social determinants of health; UCSF, University of California, San Francisco; VEM, Vaccine Equity Metric; Vaccination; ZCTA, Zip Code Tabulation Area.