[Cost-benefit analysis of vaccinal prevention of hepatitis B policy]

Morbidity and mortality related to hepatitis B (VHB) induce heavy costs even in low endemia countries as France. Recent changes in patterns of virus transmission (increasing heterosexual contamination) lead to discuss the opportunity of re-evaluation of current VHB vaccine policies aiming primarily at most exposed populations (patients under dialysis, hospital workers, infants born to VHB+ mothers). Using cost-benefit methodology, in a context where epidemiological and economical pertinent data are quite rare, this article evaluates different strategies ("no vaccination", "universal vaccination" and "vaccination after screening") for four different populations with contrasted exposure (French general population, young men adults, homosexual men and intravenous drug users). The cost-benefit ratios indicate that thresholds are, for low-risk populations, very far from usually accepted values attributed to epidemiological and economical parameters. If vaccine is administrated to young men adults, the cost-per-hepatitis saved relative to "no vaccination" is 36,000 F. For high-risk exposure groups, vaccination may be considered cost-benefit for attack rates near (homosexual men) or greater (drug users) than that observed; optimal strategy could be obtained if drug users are screened and vaccined. This is the result of combination of relatively low incidence of VHB and variability of medical course and chronic sequalae. Consequently, if universal vaccination has to be chosen, it would mean that the implicit value attributed to the prevention of one hepatitis is very high.