Modeling the potential public health and economic impact and cost-effectiveness of vaccination strategies using a COVID-19 vaccine in Costa Rica.

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 Costa Rica, this study estimated the outcomes of different vaccination strategies with BNT162b2 COVID-19 mRNA vaccine, 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 implemented variation in COVID-19 incidence and sensitivity analyses were both conducted to assess uncertainty.

RESULTS Compared to no adapted vaccine, the vaccination strategy in older adults aged ≥65 years and the high-risk population aged 18-64 years was estimated to prevent 3704 symptomatic cases, 3670 outpatient cases, 35 hospitalizations, 102 lost quality-adjusted life-years (QALYs), and one death, translating to total direct and societal cost savings of US$9,465,324 and US$10,569,883, respectively. Expanding vaccination to adults aged ≥60 years and high-risk individuals aged 18-59 years further increased benefits.

CONCLUSIONS Implementing an adapted COVID-19 vaccine strategy for high-risk and older adults in Costa Rica is expected to be cost-saving, with broader age group eligibility yielding even greater benefits.