Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Sep 28;19(19):12304.
doi: 10.3390/ijerph191912304.

Effects of Social Vulnerability and Spatial Accessibility on COVID-19 Vaccination Coverage: A Census-Tract Level Study in Milwaukee County, USA

Zengwang Xu  1 , Bin Jiang  2
Affiliations

Effects of Social Vulnerability and Spatial Accessibility on COVID-19 Vaccination Coverage: A Census-Tract Level Study in Milwaukee County, USA

Zengwang Xu et al. Int J Environ Res Public Health. .

Abstract

COVID-19 vaccination coverage was studied by race/ethnicity, up-to-date doses, and by how it was affected by social vulnerability and spatial accessibility at the census-tract level in Milwaukee County, WI, USA. Social vulnerability was quantified at the census-tract level by an aggregate index and its sub-components calculated using the principal components analysis method. The spatial accessibility was assessed by clinic-to-population ratio and travel impedance. Ordinary least squares (OLS) and spatial regression models were employed to examine how social vulnerability and spatial accessibility relate to the vaccination rates of different doses. We found great disparities in vaccination rates by race and between areas of low and high social vulnerability. Comparing to non-Hispanic Blacks, the vaccination rate of non-Hispanic Whites in the county is 23% higher (60% vs. 37%) in overall rate (one or more doses), and 20% higher (29% vs. 9%) in booster rate (three or more doses). We also found that the overall social-vulnerability index does not show a statistically significant relationship with the overall vaccination rate when it is defined as the rate of people who have received one or more doses of vaccines. However, after the vaccination rate is stratified by up-to-date doses, social vulnerability has positive effects on one-dose and two-dose rates, but negative effects on booster rate, and the effects of social vulnerability become increasingly stronger and turn to negative for multi-dose vaccination rates, indicating the increasing challenges of high social vulnerability areas to multi-dose vaccination. The large negative effects of socio-economic status on the booster rate suggests the importance of improving general socio-economic conditions to promote multi-dose vaccination rates.

Keywords: COVID-19; Milwaukee; disparity; social vulnerability; vaccination.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Spatial distribution of the proportions of non-Hispanic Whites (a), Blacks and Hispanics (b) in census tracts in Milwaukee County (based on 2020 census redistricting summary file).
Figure 2
Figure 2
Spatial distribution of the score of the three major principal components (PCs): (a) PC1 representing general socio-economic status (SES); (b) PC2 representing Hispanics; (c) PC3 representing non-Hispanic Blacks; and (d) the value of the overall social vulnerability index (SVI) in census tracts in Milwaukee.
Figure 3
Figure 3
Spatial distribution of high and low social vulnerability areas based on (a) quartile and (b) head/tail breaks classification of the social vulnerability index. The red color (i.e., the fourth quarter or the large-value head class) represents high social vulnerability, and the green color (i.e., the first quarter or the small-value tail) represents low social vulnerability.
Figure 4
Figure 4
Age-adjusted vaccination rates in census tracts in Milwaukee: (a) overall rate; (b) one-dose rate; (c) two-dose rate; and (d) booster rate.
Figure 5
Figure 5
(a) Spatial location of the vaccination clinics, (b) tract-level clinic-to-population ratio, and (c) tract-level mean shortest travel distance to three nearest clinics.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Li Y., Li M., Rice M., Su Y., Yang C. Phased implementation of COVID-19 vaccination: Rapid assessment of policy adoption, reach and effectiveness to protect the most vulnerable in the US. Int. J. Environ. Res. Public Health. 2021;18:7665. doi: 10.3390/ijerph18147665. - DOI - PMC - PubMed
    1. Shim E. Projecting the impact of SARS-CoV-2 variants and the vaccination program on the fourth wave of the COVID-19 pandemic in South Korea. Int. J. Environ. Res. Public Health. 2021;18:7578. doi: 10.3390/ijerph18147578. - DOI - PMC - PubMed
    1. Sycinska-Dziarnowska M., Paradowska-Stankiewicz I., Woźniak K. The global interest in vaccines and its prediction and perspectives in the era of COVID-19. Real-time surveillance using Google Trends. Int. J. Environ. Res. Public Health. 2021;18:7841. doi: 10.3390/ijerph18157841. - DOI - PMC - PubMed
    1. Lin L., Zhao Y., Chen B., He D. Multiple COVID-19 waves and vaccination effectiveness in the united states. Int. J. Environ. Res. Public Health. 2022;19:2282. doi: 10.3390/ijerph19042282. - DOI - PMC - PubMed
    1. Gonzales A., Lee E.C., Grigorescu V., Smith S.R., De Lew N., Sommers B.D. Overview of Barriers and Facilitators in COVID-19 Vaccine Outreach. US Department of Health and Human Services; Washington, DC, USA: 2021.