Calculation of the possible reduction in morbidity and mortality (PRMM) for each vaccine. These figures represent vaccine preventable illness values adjusted for the predicted efficacy of the vaccine. For diseases in which vaccine efficacy is expected to be the same for all conditions, calculation of PRMM simply involves multiplying the vaccine preventable illness values (one for each IME perspective) by the efficacy. If the vaccine is expected to have different efficacies for different conditions, the calculations are more complex. PRMM values must be calculated separately for each morbidity category/age group combination and then added together.