Cost-effectiveness of vaccinating for invasive pneumococcal disease in the elderly in the Lazio region of Italy.

Pneumococcal vaccination among the elderly is currently recommended in several western countries. We estimated the cost-effectiveness of a hypothetical vaccination campaign of 65+ year olds in the Lazio region (Italy). Baseline net costs per event averted and life-year gained, at 2001 prices, were euro 34,681 (95%CI: euro 28,699 to euro 42,929) and euro 23,361, respectively (95%CI: euro 16,419 to euro 38,297). Lower bacteraemic pneumonia incidence and vaccine effectiveness increased the net cost per life-year gained (ICER) to euro 53,899 and euro 74,313, respectively; in the best-case scenario the ICER was euro 4249. The case definition of invasive pneumococcal disease and, consequently, vaccine effectiveness are major uncertainties in countries with low incidence of pneumonia.