Cost-benefit analysis of a strategy to vaccinate healthy working adults against influenza

Background: Influenza is a major cause of illness, disruption to daily life , and work absenteeism among healthy working adults aged between 18 and 64 years. This group is not included among the traditional priority groups for annual vaccination. Immunization rates remain low. Objective: To assess the economic implications of a strategy for annual vac cination of this group. Methods: Using the societal perspective, this cost benefit analysis include d the direct and indirect costs associated with vaccination as well as the direct and indirect costs prevented by vaccination. Clinical and economic v ariable estimates were derived primarily from the published literature. For this model, it was assumed that vaccination occurred in efficient, low-cos t settings such as at the work site. Monte Carlo simulation was used to cal culate the mean net costs or savings along with the 95% probability interva l, and sensitivity analyses explored the sensitivity of the cost model to d ifferent values of the input variables. Results: Vaccinating healthy working adults was on average cost saving, wit h mean savings of $13.66 per person vaccinated (95% probability interval: n et savings of $32.97 to net costs of $2.18), with vaccination generating ne t savings 95% of the time. The model was most sensitive to the influenza il lness rate, the work absenteeism rate due to influenza, and hourly wages. I n the worst-case scenario vaccination was not cost saving. Vaccination also generated net costs to society during years with a poor vaccine-circulatin g virus strain match. In all of the other sensitivity analysis scenarios, v accination was cost saving. Conclusion: Influenza vaccination of healthy working adults on average is c ost saving. These findings support a strategy of routine, annual vaccinatio n for this group, especially when vaccination occurs in efficient and low c ost sites.