Patterns and predictors of COVID-19 vaccine uptake among United States active duty Service members, 2020-2022: Implications for future pandemics

IntroductionVaccine mandates have been used to minimize the duty days lost and deaths attributable to infectious disease among active duty Service members (ADSMs). In response to the global COVID-19 pandemic, in August 2021, the United States Department of Defense issued a COVID-19 vaccine mandate for all ADSMs. This study aimed to investigate COVID-19 vaccine uptake among the ADSM population, as well as factors associated with timing of COVID-19 vaccine receipt. MethodsThis study included ADSMs on active duty between 1/1/2020-6/30/2022. Univariate analyses investigated associations between demographic factors (age, sex, race, ethnicity, branch of service, rank, state of residence) and COVID-19 diagnosis with the following outcomes: 1) time to primary series initiation in relation to the DoD vaccine mandate, 2) time between doses of the two-dose primary series, and 3) time between booster eligibility and receipt ResultsA total of 1,799,466 ADSMs were included, with 90% receiving [≥]1 COVID-19 vaccine dose during the study period and 77% initiating the primary series prior to the mandate. Over 80% of ADSMs received a complete primary series, with 96% of those adhering to the recommended regimen. History of COVID-19 diagnosis was associated with later receipt of all doses. ConclusionsCOVID-19 vaccine uptake was high among all ADSMs, with the majority initiating the primary series before the mandate. The high vaccine uptake among ADSMs shown here may be used as a guide to both military and civilian pandemic policy and outreach efforts related to enhanced vaccine uptake.