Marshfield Clinic Research Foundation, Marshfield, Wisconsin, USA.
PLoS One. 2013 Aug 26;8(8):e72243. doi: 10.1371/journal.pone.0072243. eCollection 2013.
Studies of influenza vaccine effectiveness in schools have assessed all-cause absenteeism rather than laboratory-confirmed influenza. We conducted an observational pilot study to identify absences due to respiratory illness and laboratory-confirmed influenza in schools with and without school-based vaccination.
A local public health agency initiated school-based influenza vaccination in two Wisconsin elementary schools during October 2010 (exposed schools); two nearby schools served as a comparison group (non-exposed schools). Absences due to fever or cough illness were monitored for 12 weeks. During the 4 weeks of peak influenza activity, parents of absent children with fever/cough illness were contacted and offered influenza testing.
Parental consent for sharing absenteeism data was obtained for 937 (57%) of 1,640 students. Fifty-two percent and 28%, respectively, of all students in exposed and non-exposed schools were vaccinated. Absences due to fever or cough illness were significantly lower in the exposed schools during seven of 12 surveillance weeks. Twenty-seven percent of students at exposed schools and 39% at unexposed schools had one or more days of absence due to fever/cough illness (p<0.0001). There was no significant difference in the proportion of students absent for other reasons (p = 0.23). During the 4 week period of influenza testing, respiratory samples were obtained for 68 (42%) of 163 episodes of absence due to fever or cough illness. Influenza was detected in 6 students; 3 attended exposed schools.
Detection of laboratory-confirmed influenza in schools was challenging due to multiple consent requirements, difficulty obtaining samples from absent children, and a mild influenza season. School-based influenza vaccination was associated with reduced absenteeism due to fever or cough illness, but not absenteeism for other reasons. Although nonspecific, absence due to fever or cough illness may be a useful surrogate endpoint in school-based studies if identification of laboratory confirmed influenza is not feasible.
在学校中进行的流感疫苗有效性研究评估了所有原因的缺勤率，而不是实验室确诊的流感。我们进行了一项观察性试点研究，以确定在有和没有学校为基础的疫苗接种的学校中因呼吸道疾病和实验室确诊的流感导致的缺勤情况。
当地公共卫生机构在 2010 年 10 月（暴露学校）在威斯康星州的两所小学启动了学校为基础的流感疫苗接种；两所附近的学校作为对照组（非暴露学校）。监测了 12 周的发热或咳嗽疾病缺勤情况。在流感活动高峰期的 4 周内，联系有发热/咳嗽症状的缺勤儿童的家长，并提供流感检测。
获得了 1640 名学生中 937 名（57%）的家长同意分享缺勤数据。暴露学校和非暴露学校的所有学生中，分别有 52%和 28%接受了疫苗接种。在 12 周监测周中的 7 周内，暴露学校的发热或咳嗽疾病缺勤率显著降低。暴露学校的 27%的学生和非暴露学校的 39%的学生因发热/咳嗽疾病缺勤 1 天或以上（p<0.0001）。因其他原因缺勤的学生比例没有显著差异（p=0.23）。在流感检测的 4 周期间，因发热或咳嗽疾病缺勤的 163 例中，有 68 例（42%）获得了呼吸道样本。在 6 名学生中检测到了流感；其中 3 人就读于暴露学校。
由于需要多重同意要求、难以从缺勤儿童获得样本以及流感季节温和，在学校中检测实验室确诊的流感具有挑战性。学校为基础的流感疫苗接种与发热或咳嗽疾病缺勤率降低相关，但与其他原因的缺勤无关。尽管非特异性，发热或咳嗽疾病缺勤可能是学校为基础的研究中的有用替代终点，如果无法确定实验室确诊的流感。
