Modeling the potential public health and economic impact and cost-effectiveness of vaccination strategies using an adapted COVID-19 vaccine in the Dominican Republic

BACKGROUND: Using adapted COVID-19 vaccines targeting current variants in circulation is necessary for addressing the dynamic evolution of the SARS-CoV-2 virus and protecting against emerging variants. RESEARCH DESIGN AND METHODS: Using a previously published combined Markov-decision tree model adapted for the Dominican Republic, this study estimated the outcomes of different vaccination strategies targeting various age and risk groups. The model used age-specific epidemiology, clinical, cost, and quality-of-life inputs derived from the published literature and national surveillance data. Scenario analyses that included variations in the incidence of COVID-19 and sensitivity analyses were conducted to assess uncertainty. RESULTS: Compared to no vaccination, the vaccination strategy targeting adults aged ≥65 years and the high-risk population was estimated to prevent 9,272 symptomatic cases, 9,184 outpatient cases, 88 hospitalizations, 239 lost quality-adjusted life-years (QALYs), and three deaths, translating to total direct and societal cost savings of US$11,064,184 and US$12,662,370, respectively. Expanding vaccination to adults aged ≥60 years and high-risk individuals aged 18-59 years further increased public health and economic benefits. CONCLUSIONS: Implementing an adapted COVID-19 vaccine strategy for high-risk and adults aged ≥65 in the Dominican Republic is expected to be cost-saving, with broader age group coverage yielding even greater benefits.