EFFICACY OF VARICELLA VACCINE IN CLINICAL PRACTICE

水痘疫苗在临床实践中的功效

• 批准号: 6373667
• 负责人: EUGENE David SHAPIRO
• 金额: $ 37.48万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6373667
• 关键词: Herpesviridae vaccine; adolescence (12-20); age difference; chickenpox; child (0-11); clinical research; communicable disease control; drug screening /evaluation; human population study; human subject; immunofluorescence technique; medical records; polymerase chain reaction; sign /symptom; varicella zoster virus

DESCRIPTION: Live, attenuated varicella vaccine was licensed in March, 1995 for use in healthy individuals in the United States. There has been controversy about both its short-term and its long-term efficacy (in part because licensure was based on limited data, much of which was from studies with a vaccine that contained a higher concentration of virus). Consequently, many physicians have been reluctant to use the vaccine, although routine immunization of all susceptible, immunocompetent children (beginning at 12 months of age) has been recommended by the U.S. Public Health Service Advisory Committee on Immunization Practices and by other advisory committees. The primary purpose of the proposed study is to assess the protective efficacy of this varicella vaccine, as it is used in actual practice, and to assess the effects of both age at the time of vaccination and of the time since vaccination on vaccine efficacy. This will be a case-control study in which the cases will be immunocompetent children from 15 months-16 years of age who develop varicella. The cases will be identified through active surveillance conducted at both private practices and health maintenance organizations in greater New Haven, Connecticut, and in Westchester County, New York. A research assistant will visit the home of each potential case subject on the third day of the rash to assess the severity of the illness by use of a scale based on pre-defined criteria (e.g., number of vesicles, elevation of fever, etc.). In addition, material from the lesions will be tested with both a direct fluorescent antibody test and polymerase chain reaction (to confirm the presence of varicella-zoster virus and to determine whether it is wild-type or vaccine-type virus). The controls will be immunocompetent children without a history of chickenpox who are matched (2:1) to the cases by both age and the source of primary care. The medical records of both the cases and the controls will be reviewed to determine whether they had received varicella vaccine. The protective efficacy of the vaccine (and the associated 95% confidence interval) will be estimated from the matched odds ratios. The estimates will be adjusted for possible confounders with the use of conditional logistic regression. The effects on the efficacy of the vaccine of both age at the time of vaccination and the time since vaccination will be assessed by stratification and by multivariate analysis. Additionally, differences in the clinical severity of varicella (as determined by the clinical scale) among vaccinated and unvaccinated cases will be assessed. This study will provide important information about the efficacy of varicella vaccine in actual practice. Such information is critical for assessing the cost-effectiveness of the vaccine and will be useful both for educating physicians and for counselling parents who may be concerned about having their children vaccinated.

描述：水痘减毒活疫苗于 1995 年 3 月获得许可 用于美国的健康个体。 已经有 关于其短期和长期疗效的争议（部分 因为许可基于有限的数据，其中大部分来自研究 使用含有更高浓度病毒的疫苗）。 因此，许多医生一直不愿意使用该疫苗， 尽管对所有易感、免疫功能健全的儿童进行常规免疫接种 （从 12 个月大时开始）已被美国公众推荐 卫生服务免疫实践咨询委员会和其他机构 咨询委员会。 拟议研究的主要目的是评估 这种水痘疫苗的保护功效，因为它在实际使用中 实践，并评估接种疫苗时年龄的影响 以及接种疫苗后的时间对疫苗功效的影响。 这将是一项病例对照研究，其中的病例具有免疫功能 患有水痘的 15 个月至 16 岁儿童。 案例 将通过在私人和私营部门进行的主动监视来识别 大纽黑文地区的实践和健康维护组织， 康涅狄格州和纽约州韦斯特切斯特县。 研究助理将 在皮疹发生的第三天拜访每个潜在病例的家 使用基于预定义的量表评估疾病的严重程度 标准（例如水泡数量、发烧程度等）。此外， 来自病变的材料将使用直接荧光进行测试 抗体测试和聚合酶链反应（以确认是否存在 水痘带状疱疹病毒并确定它是野生型还是 疫苗型病毒）。 对照组将是没有病史的免疫功能正常的儿童 年龄和来源与病例匹配（2:1）的水痘患者 初级保健。 病例和对照的医疗记录将 接受审查以确定他们是否接种了水痘疫苗。 这 疫苗的保护功效（以及相关的 95% 置信度） 间隔）将根据匹配的优势比进行估计。 估计 将使用条件调整可能的混杂因素 逻辑回归。 两种年龄对疫苗功效的影响 将评估接种疫苗时和接种后的时间 通过分层和多变量分析。 另外，差异 水痘的临床严重程度（由临床量表确定） 将评估已接种疫苗和未接种疫苗的病例。 这项研究将 提供有关水痘疫苗功效的重要信息 实际练习。 此类信息对于评估 疫苗的成本效益，并且对于教育都有用 医生以及为可能担心的父母提供咨询 他们的孩子接种了疫苗。