Abstract
Background and Objectives: While prior research has linked individual chronic conditions to higher COVID-19 vaccine uptake, little is known about how multimorbidity influences both primary vaccine series and booster uptake. This study aims to evaluate the association between multimorbidity and COVID-19 vaccination and booster behaviors among adults in the United States.
Methods: A cross-sectional analysis was conducted using the 2022 Medical Expenditure Panel Survey (MEPS), a nationally representative dataset. Adults aged ≥18 years with complete data on vaccination, booster status, and chronic conditions were included (n = 17,172). COVID-19 vaccination and booster statuses were self-reported. Chronic disease conditions were categorized as none, one, or two or more chronic conditions (i.e., multimorbidity). Covariates included age, sex, race and ethnicity, social determinants of health, pain level, and lifestyle variables. Survey-weighted logistic regression models were used to estimate unadjusted and adjusted odds ratios (AOR) for vaccine and booster uptake associated with multimorbidity.
Results: After adjusting for all covariates, adults with multimorbidity had significantly higher odds of receiving the primary COVID-19 vaccine series compared to those with a single chronic condition (AOR = 1.28, 95% CI: 1.07–1.53, p = 0.0045). In contrast, multimorbidity was not significantly associated with booster uptake (AOR = 0.95, 95% CI: 0.81–1.12, p = 0.5458).
Conclusions: Multimorbidity is independently associated with increased uptake of the primary COVID-19 vaccine series but not with booster vaccination. These findings highlight the need for targeted strategies to promote booster uptake among individuals with multiple chronic conditions.