Should British soldiers be vaccinated against hepatitis A? An economic analysis.

We conducted a study to analyse the efficiency of introducing vaccination against hepatitis A to the schedule for troops in the British Army. The study design included a cost-effectiveness analysis (CEA) of cost per case avoided comparing active and passive immunization and a cost-benefit analysis (CBA). The study population comprised all British Army personnel as well as those soldiers assumed to be deployed to high-risk areas a variable number of times in 5 years. The average cost of one case of hepatitis A avoided by vaccination was calculated and compared with the average cost of achieving the same outcome by passive immunization. In a 5-year four-exposure scenario at a low incidence and using a 3% discount rate, avoiding one case of hepatitis A by vaccination would cost 52,865 pounds, against 97,305 pounds by passive immunization. The equivalent cost-benefit ratios are 13.4 for gammaglobulin and 7.2 for vaccine. For fewer exposures the break-even point for vaccine is two exposures in 4 years. Although our estimates are sensitive to direct costs and relatively sensitive to the estimated incidence, vaccinating troops against hepatitis A appears to be a more efficient procedure than passive immunization, especially as a long-term investment in troops likely to effect several operational deployments. Given the difficulty of forecasting which troops would deploy, the best-buy strategy may be vaccination of troops most likely to deploy repeatedly.