Unraveling the Relationship between Social Vulnerability Index and COVID-19 Prevalence in Southern Nevada

The COVID-19 pandemic was a catastrophic global event that exacerbated public health issues and disparities, especially in socially vulnerable communities. Thus, this study examines areas classified by the CDC's Social Vulnerability Index (SVI) metric, which assesses vulnerable communities experiencing adverse events through sixteen social determinants that impact health. The purpose of this study will be to determine if (1) COVID-19 testing rates and/or COVID-19 vaccination rates mediate SVI and COVID-19 prevalence rates and (2) if COVID-19 testing rate and COVID-19 vaccination rates serially mediate SVI and COVID-19 prevalence rates. In order to achieve this, census tracts within Southern Nevada will be analyzed from January 2020 to June 2022. Mediation analyses with linear regression were employed to examine complex relationships among SVI, COVID-19 testing, vaccination, and prevalence rates. The 95% confidence intervals of indirect effects were particularly computed using a bootstrap technique to determine whether a mediator was statistically significant. Results display that the COVID-19 testing rate (indirect effect = -3.98; 95% CI = -7.43, -0.11), COVID-19 full-vaccination rate (indirect effect = -1.88; 95% CI = -7.54, -0.95), and COVID-19 follow-up vaccination rate (indirect effect = -11.52; 95% CI = -15.97, -6.49) negatively mediates the relationship between SVI and COVID-19 prevalence rate. Our serial mediation analysis showed that an increase in SVI was significantly inversely associated with a significant total indirect effect of -0.02 (95% CI = -0.03, -0.002) from the sequential pathway from COVID-19 testing rate, COVID-19 full vaccination rate, and COVID-19 follow-up vaccination rate as serial mediators. These findings further highlight the impact of infectious outbreaks from access to vaccination and testing resources in socially vulnerable communities, underscoring the need for public health professionals to develop sustainable interventions.