Predicting cost-benefits before programs are started: looking at conjugate vaccine for invasive pneumococcal infections.

This analysis uses existing data to examine how an analysis to predict the net financial impact for an emerging medical program, namely a conjugate vaccine against Streptococcus pneumoniae, and to identify which key variables will have the greatest impact on the program's costs and benefits. Using data available on the prevalence and case fatality rates for invasive diseases caused by S pneumoniae, we examined the theoretical economic impact of vaccinating all newborns versus not vaccinating. Effectiveness estimates for conjugated pneumococcal vaccines and disease incidence and fatality rates were obtained from published sources. Because of scanty or inconclusive data for otitis media and pneumonia, the analysis was limited to cases of meningitis and bacteremia due to S pneumoniae. Based on these two diseases alone, immunization with conjugate pneumococcal vaccine could save an estimated 222 lives per million children vaccinated per year. Analysis of direct costs (projected immunization costs minus savings from reduced illness) show that a pneumococcal vaccine program will result in net direct costs between $0.08 and $2.42 per child. When indirect costs are included in the analysis, the vaccine is cost savings for all cases except when the two year incidence of disease and death rates are lowest and the cost of the vaccine series is $150. Further research should focus on these key issues as the vaccine is introduced into use, as expected in the next few years.