Methods for risk-benefit and cost-benefit analysis of vaccinations.

The basic aim of vaccination is to prevent more severe complications of the respective disease than might be caused by the vaccine itself. Following this idea formulae were developed for calculation of the risk ratio Q and the risk difference D. The following parameters are considered in this formulae: risk of the disease (R), risk of vaccination (r), protection rate (p) and duration of protection (t). Besides, for calculations with partially vaccinated populations the immunization rate "I" has to be considered. A vaccination is beneficial if Q greater than 1.0 and D greater than 0. If vaccinations have proved to be valuable from the medical point of view, additional cost-benefit calculations may be of great importance for socio-economic considerations. Consequently, the above mentioned formulae were modified for calculation of the benefit cost ratio (Qc) and the benefit cost difference (Dc) for monovalent as well as for bivalent vaccines.