[Cost-benefit ratio of tick-borne encephalitis vaccination of French troops based in Kosovo].

BACKGROUND

French military troops based in Kosovo are exposed to Tick-Borne Encephalitis (TBE) biorisk. An efficacious vaccine is available to prevent this disease, burdened by high morbidity and mortality. The epidemiologic features of TBE in Kosovo are unprecise. To help the French Department of Defense to make a decision about immunization against TBE, we performed a cost-benefit analysis.

METHODS

By a Bayes'analysis decision, we have estimated the net benefits for a three-injection vaccine program versus absence of vaccination, for all French military troops based in Kosovo. Time expectancy was 4 years. Through the review of several medical reports, we have estimated the useful parameters for this study: morbidity incidence rate, mortality rate, sequelae rate, efficacy vaccine and side effects. We have chosen as initial hypothesis a sero-conversion rate of 1,080 per 100,000 men-by-year. Human life was valorized in francs, by calculating the allowance paid by Department of Defense to the family in case of death or for sequelae.

RESULTS

Net benefits arised to 2.17 millions of francs. The vaccine program cost was 25.0 millions of francs. 140 cases of encephalitis viruses were saved by vaccination. Nevertheless a sensibility analysis has shown that results are well reliable with TBE incidence rate.

CONCLUSION

The break even point being close to the incidence rate of the initial assumption, the decision to vaccine all French military troops depends at the same time on a better knowledge of the incidence of the disease in Kosovo, but also of the number of potentially avoided cases of tick-borne encephalitis and of the programs of vaccination concerning this disease of the other countries forming the United Nations Organization forces.