Cost-effectiveness of varicella vaccination programs: an update of the literature.

Varicella is one of the most common infectious diseases in childhood, caused by the varicella zoster virus. Although vaccines are available, there are only a few countries with an early-childhood vaccination program. Most countries mainly focus on vaccination of high-risk groups, such as susceptible healthcare workers. One of the main concerns with a routine early-childhood vaccination program is a potential (temporal) increase of the incidence of herpes zoster among elderly adults. In this review, we focus on the cost-effectiveness of varicella vaccination and on the methodology used in the health-economic studies. In particular, we focus on the perspective adopted, type of model used, the modeled effect on herpes zoster, the vaccine efficacy and price, and on the value of time lost by infection. The vast majority of studies show vaccination of high-risk groups - including susceptible adolescents - to be cost saving. Routine early-childhood vaccination programs are always cost saving if indirect costs of production losses are included, or cost effective, as long as the potential negative effects on zoster are not taken into account. We note that most studies included in the review used old vaccine prices and a single dose of the varicella vaccine, whereas multiple doses are now becoming the standard. Despite that, those aspects limit the timeliness of our review and we believe that the current work does provide useful insights in the cost-effectiveness of varicella vaccination.