Universal vaccination of children against hepatitis A in Chile: a cost-effectiveness study.

OBJECTIVE To evaluate the healthcare and economic impact of routine hepatitis A vaccination of toddlers in Chile. METHODS We used a dynamic model of hepatitis A infection to evaluate the impact of a two-dose vaccination program, administered at ages 12 and 18 months. The model incorporated the changing epidemiology of hepatitis A in Chile and the development of vaccine-induced herd immunity. Our analysis was conducted from the public payer perspective, and an estimation of the societal perspective was performed. Costs are expressed in 2005 U.S. dollars. RESULTS Vaccination of toddlers rapidly reduced the healthcare burden of hepatitis A. In the base case (95% vaccination coverage, 100-year time horizon, 1% annual decrease in force of infection), the average number of infections fell by 76.6% annually, and associated deaths fell by 59.7%. Even at 50% coverage, the program reduced infection rates substantially. Routine vaccination of toddlers had economic as well as health benefits, saving $4,984 per life-year gained (base case scenario). The program became cost saving after 6 years, and its overall cost-effectiveness per life-year gained was largely unaffected by changes in disease-related costs, herd immunity, coverage rate, and annual decrease in force of infection. CONCLUSIONS Routine vaccination of toddlers will reduce the rates of symptomatic hepatitis A and associated mortality. The two-dose schedule evaluated here will be less expensive than disease-related costs in the absence of vaccination from the sixth year of its implementation. These findings support the establishment of a routine vaccination program for toddlers in Chile.