Abstract
OBJECTIVES: Understanding the differential burden of pediatric SARS-CoV-2 infection by social factors is important to guide public health action. We evaluated the associations between county-level social vulnerability and infection-induced SARS-CoV-2 antibody seroprevalence and how associations changed over time. METHODS: We analyzed pediatric national serosurvey data from 50 US states, the District of Columbia, and Puerto Rico from September 2021 through December 2022 (N = 216 273). Specifically, we estimated adjusted prevalence ratios (APRs) of SARS-CoV-2 antibody seropositivity across terciles of overall county Social Vulnerability Index (SVI) scores and vulnerability scores across the 4 SVI domains: socioeconomic status, household characteristics, racial and ethnic minority status, and housing and transportation. We conducted multilevel mixed-effects Poisson models with robust variance estimation of the association of seropositivity with scores for SVI and its domains over time, adjusting for age, sex, rural/urban status, US Census region, and county vaccination rates. RESULTS: In September 2021, children residing in the highest (APR = 1.4) and medium (APR = 1.2) tercile counties by SVI score were more likely to have serologic evidence of past SARS-CoV-2 infection than those residing in the lowest tercile counties. This association attenuated over time; domain-specific vulnerability scores for socioeconomic status and household characteristics displayed similar associations and temporal patterns. CONCLUSIONS: Our findings demonstrate the dynamic nature of pediatric health during a public health emergency. The results reinforce the importance of data systems that allow public health agencies to be responsive through tailored strategies to support children experiencing the greatest health effects, thereby advancing opportunities for all people to attain their highest level of health.