Cost-effectiveness analysis of preventive vaccination against tick-borne encephalitis in Latvian adults

Background: Latvia experiences high nationwide incidence rates of tick-born encephalitis (TBE) infection and is
one of the highly endemic European countries. Despite the availability of preventive vaccination against the TBE,
the infection rate has increased during the last decade. TBE disease is associated with permanent neurological
damage requiring specialized healthcare over the lifetime of those affected. In Latvia state-funded vaccination is
provided only to children living in endemic areas and to orphans. The aim of this paper is to determine costeffectiveness of preventive vaccination in Latvian adults.
Methods: We developed a decision analytic model to assess the cost-effectiveness of a preventive TBE vaccination
in Latvian adults. Patients were divided in two equal cohorts of vaccinated and unvaccinated individuals aged
≥18 years. A mixed model structure was employed to calculate direct treatment costs and outcomes in the
symptomatic disease phase and to estimate long-term costs and health outcomes. Total estimated treatment costs
in euros and outcomes as Quality-adjusted Life Years (QALYs) over a lifetime horizon were compared between
cohorts and the base-case analysis result presented as the incremental cost-effectiveness ratio (ICER) from the
healthcare provider's perspective.
Results: The base-case analysis shows that preventive vaccination against TBE infection is dominant when
compared to a no vaccination strategy in the Latvian adult population. The findings of sensitivity analysis suggest
that changes in selected parameters do not significantly affect the result.
Conclusions: Given the recommended vaccination schedule, preventive vaccination against TBE infection in
Latvian adults is dominant from the healthcare provider's perspective.