Effectiveness of Varicella Vaccine in Clinical Practice

水痘疫苗在临床实践中的有效性

• 批准号: 6895675
• 负责人: EUGENE David SHAPIRO
• 金额: $ 15.81万
• 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 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6895675
• 关键词: Herpesviridae vaccine; adolescence (12-20); age difference; chickenpox; child (0-11); clinical research; communicable disease control; cost effectiveness; human population study; human subject; human therapy evaluation; immunofluorescence technique; medical records; patient oriented research; polymerase chain reaction; vaccine evaluation; varicella zoster virus

DESCRIPTION (provided by applicant): Live attenuated varicella vaccine was approved in March, 1995 and has been recommended for routine use in susceptible, healthy persons 12 months of age. In the first four years of this study, we have demonstrated that the effectiveness of varicella vaccine in clinical practice was 85 percent overall and 97 percent against moderate or severe disease. Vaccinees who developed varicella generally had very mild disease. However, there continues to be uncertainty about the long-term effectiveness of the vaccine. The primary purpose of the proposed study is to assess the effect of time since vaccination and of age at the time of vaccination on the effectiveness of varicella vaccine as it is used in actual practice. This will be a continuation of a case-control study in which the cases will be immunocompetent children from 13 months to 18 years of age who develop varicella. The cases will be identified through active surveillance of pediatric practices in Connecticut. 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. In addition, material from the lesions will be tested with the polymerase chain reaction test 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 varicella who are matched to the cases (2 controls/case) by both age and pediatric practice. The medical records of both the cases and the controls will be reviewed to determine whether the child had received varicella vaccine. The effectiveness of the vaccine will be estimated from the matched odds ratios. The effects on the effectiveness of the vaccine of both age at the time of vaccination and time since vaccination will be assessed by conditional logistic regression. The estimates will be adjusted for possible confounders with the use of conditional logistic regression. In addition, differences in the clinical severity of varicella among vaccinated and unvaccinated cases will be assessed, as will whether the severity of disease among vaccinees is affected by either time since vaccination or age at the time of vaccination. This study will provide important information about the effectiveness of varicella vaccine over time that is critical for assessing the cost-effectiveness of the vaccine and the possible need for booster doses, and will be useful both for educating physicians and for counseling parents about having their children vaccinated.

说明（由申请人提供）：水痘减毒活疫苗于 1995 年 3 月获得批准，并被推荐在 12 个月大的易感健康人群中常规使用。在这项研究的前四年中，我们已经证明水痘疫苗在临床实践中的总体有效性为 85%，针对中度或重度疾病的有效性为 97%。患上水痘的疫苗接种者通常病情非常轻微。然而，疫苗的长期有效性仍然存在不确定性。拟议研究的主要目的是评估接种后的时间和接种时的年龄对水痘疫苗在实际使用中的有效性的影响。这将是病例对照研究的延续，其中的病例将是 13 个月至 18 岁、患有水痘、免疫功能正常的儿童。这些病例将通过对康涅狄格州儿科实践的积极监测来发现。研究助理将在皮疹发生的第三天拜访每个潜在病例的家中，以评估疾病的严重程度。此外，还将对来自病灶的材料进行聚合酶链反应测试，以确认水痘带状疱疹病毒的存在，并确定其是野生型病毒还是疫苗型病毒。对照将是没有水痘病史、免疫功能正常的儿童，他们在年龄和儿科实践方面与病例（2 个对照/病例）相匹配。将审查病例和对照的医疗记录，以确定儿童是否接种了水痘疫苗。疫苗的有效性将根据匹配的优势比来估计。将通过条件逻辑回归评估接种时年龄和接种后时间对疫苗有效性的影响。将使用条件逻辑回归对可能的混杂因素进行调整。此外，还将评估已接种疫苗和未接种疫苗的病例中水痘临床严重程度的差异，以及接种疫苗者的疾病严重程度是否受接种后时间或接种时年龄的影响。这项研究将提供有关水痘疫苗随时间推移的有效性的重要信息，这对于评估疫苗的成本效益和加强剂量的可能需求至关重要，并且对于教育医生和为家长提供有关让孩子接种疫苗的咨询很有用。