Izurieta H S, Strebel P M, Blake P A
Division of Public Health, Georgia Department of Human Resources, Atlanta, USA.
JAMA. 1997 Nov 12;278(18):1495-9.
Because lyophilized varicella vaccine must be stored frozen at -15 degrees C or less (> or = 5 degrees F) and administered within 30 minutes after reconstitution, the potential exists for decreased vaccine effectiveness when the vaccine is used under field conditions.
To describe an outbreak of varicella in a child care center and to determine postlicensure effectiveness of varicella vaccine.
Retrospective cohort study.
A child care center in DeKalb County, Georgia, in 1996.
Of the 184 children registered in the child care center, 148 were eligible for the study based on absence of history of varicella before January 1, 1996.
Data on disease status, severity and impact of disease, and risk factors for varicella and for vaccine failure were obtained from parents and their children's pediatricians. Varicella vaccine effectiveness was calculated among children aged 12 months or older (eligible for vaccination) using the cohort method.
The outbreak started on January 17, 1996, and lasted 15 weeks. Of the 148 eligible children, 81 (55%) developed varicella. Cases among children younger than 12 months (n =7) were more severe than cases among older children. Varicella occurred in 9 (14%) of 66 vaccinated children and 72 (88%) of 82 unvaccinated children. Varicella was less severe and resulted in fewer days of absence from the child care center among vaccinated compared with unvaccinated cases. Varicella vaccine effectiveness against all forms of disease was 86% (95% confidence interval [CI], 73%-92%), and against moderate-to-severe varicella disease it was 100% (95% CI, 96%-100%). Vaccinated children with asthma or other reactive airway diseases were 7.1 times more likely to have varicella than were vaccinated children without reactive airway diseases (95% CI, 2.4-21.3).
Varicella vaccine administered under routine conditions in physicians' offices was highly effective in preventing varicella in an outbreak characterized by intense exposure. The role of asthma and other reactive airway diseases as risk factors for varicella disease and vaccine failure deserves to be investigated further.
由于冻干水痘疫苗必须在-15摄氏度或更低温度（≥5华氏度）下冷冻保存，且复溶后30分钟内必须接种，因此在现场条件下使用该疫苗时，疫苗效力可能会降低。
描述一家儿童保育中心的水痘暴发情况，并确定水痘疫苗在获得许可后的效力。
回顾性队列研究。
1996年，佐治亚州迪卡尔布县的一家儿童保育中心。
在该儿童保育中心登记的184名儿童中，148名因在1996年1月1日前无水痘病史而符合研究条件。
从家长及其孩子的儿科医生处获取有关疾病状态、疾病严重程度和影响，以及水痘和疫苗失败危险因素的数据。使用队列法计算12个月及以上（符合接种条件）儿童的水痘疫苗效力。
疫情于1996年1月17日开始，持续了15周。在148名符合条件的儿童中，81名（55%）患了水痘。12个月以下儿童（n =7）的病例比大龄儿童的病例更严重。66名接种疫苗的儿童中有9名（14%）患了水痘，82名未接种疫苗的儿童中有72名（88%）患了水痘。与未接种疫苗的病例相比，接种疫苗的病例中水痘症状较轻，在儿童保育中心缺勤的天数也较少。水痘疫苗对所有形式疾病的效力为86%（95%置信区间[CI]，73%-92%），对中度至重度水痘疾病的效力为100%（95%CI，96%-100%）。患有哮喘或其他反应性气道疾病的接种疫苗儿童患水痘的可能性是没有反应性气道疾病的接种疫苗儿童的7.1倍（95%CI，2.4-21.3）。
在医生办公室常规条件下接种的水痘疫苗在预防以高强度接触为特征的疫情中的水痘方面非常有效。哮喘和其他反应性气道疾病作为水痘疾病和疫苗失败危险因素的作用值得进一步研究。
Zotero 插件