Kim-Farley R, Bart S, Stetler H, Orenstein W, Bart K, Sullivan K, Halpin T, Sirotkin B
Am J Epidemiol. 1985 Apr;121(4):593-7. doi: 10.1093/oxfordjournals.aje.a114037.
From February 5 through April 23, 1982, 110 cases of mumps were reported among 357 students in a middle school in Ashtabula County, Ohio, an overall attack rate of 31%. Vaccine efficacy was calculated using a variety of case definitions, case surveillance systems, and vaccination-status ascertainment methods to evaluate their effects on the estimated vaccine efficacy. From data collected at the school for case ascertainment and vaccination status, clinical vaccine efficacy was initially estimated at 37%. By means of a uniform case definition (parotitis lasting two days or more) and only cases and vaccination status ascertained from parental questionnaires, estimated vaccine efficacy increased to 70%. From secondary attack rates in household members with provider-verified vaccination status, the vaccine efficacy further increased to 85%. This outbreak investigation confirms that the methods used to ascertain cases and determine vaccination status greatly affect estimates of vaccine efficacy. Studies relying solely on school records for case finding and determination of immunization status may provide misleadingly low estimates of vaccine efficacy for mumps vaccine as well as for other vaccines. Appropriate methods demonstrate that mumps vaccine is highly effective and support recommendations for its continued use.
1982年2月5日至4月23日期间，俄亥俄州阿什塔比拉县一所中学的357名学生中报告了110例腮腺炎病例，总体发病率为31%。使用多种病例定义、病例监测系统和疫苗接种状况确定方法来计算疫苗效力，以评估它们对估计的疫苗效力的影响。根据在学校收集的病例确定和疫苗接种状况数据，初步估计临床疫苗效力为37%。通过统一的病例定义（腮腺炎持续两天或更长时间）以及仅从家长问卷中确定的病例和疫苗接种状况，估计的疫苗效力提高到了70%。根据有医疗人员核实的疫苗接种状况的家庭成员的二代发病率，疫苗效力进一步提高到85%。这次疫情调查证实，用于确定病例和确定疫苗接种状况的方法极大地影响了疫苗效力的估计。仅依靠学校记录来发现病例和确定免疫状况的研究，可能会对腮腺炎疫苗以及其他疫苗的效力估计提供误导性的低估值。适当的方法表明腮腺炎疫苗非常有效，并支持继续使用该疫苗的建议。
