The Effectiveness of Evaluating Mumps Vaccine Effectiveness

mumps. If the objective is to simply decrease clinical illness, the evaluation of cases of mumps parotitis is adequate. If the goal is to interrupt transmission, subclinical cases must also be considered, because individuals with these cases shed virus [2] and presumably are capable of spreading infection. The failure of isolation of patients with mumps to prevent the spread of disease has been attributed to the shedding of virus prior to or in the absence of parotid swelling [2]. If comparisons are made between vaccinated and unvaccinated groups, the effect of prior subclinical infection should not affect efficacy estimates, because the