Influenza Vaccine Antibody Response and 6-month Persistence in Lung Transplant Recipients Using Two Definitions of Seroprotection
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 79
- 试验地点
- 1
- 主要终点
- Number of Participants with Seroprotection to Influenza Vaccine: 40 HAU
研究概览
简要总结
This a sub-study of a 5-year study designed to investigate how antibody and T cell responses following influenza vaccine compare among lung transplant patients, patients waiting for lung transplantation, and healthy individuals.
This study is designed to investigate two different definitions of influenza vaccine seroprotection at mid-season in lung transplant patients.
详细描述
Given the significant risk of morbidity and mortality, it is critical and highly recommended that lung transplant patients receive annual influenza immunizations that confer protection throughout the influenza season. Previous studies have demonstrated that transplant recipients and nonimmunocompromised populations display similar rates of seroprotection between 3 and 5 weeks after influenza vaccination, despite the transplant population achieving generally lower antibody concentrations. Two studies show influenza vaccine antibody persistence at reasonable rates at 1 year, but not 2 years, after immunization. However, there are no studies comparing seroprotection rates 6 months after vaccination, reflecting adequate coverage throughout the entire influenza season.
Seroprotection has traditionally been defined as an antibody concentration of at least 40 hemagglutination units (HAU) after vaccination, which is the criterion for influenza vaccine licensure. This concentration of antibody provides protection from infection at a rate of about 50% in typically healthy individuals. Protection from infection improves with higher antibody concentrations. For this study, a HAU of at least 160 was selected as a more conservative definition of seroprotection, where protection may reach up to 95%.
The hypothesis is that seroprotection, defined as 40 HAU or greater, will persist up to 6 months at high rates in lung transplant patients and that these rates will be comparable to the rates in healthy individuals. As a secondary outcome, seroprotection rates are compared when 160 HAU or greater was used to define seroprotection.
Influenza vaccine responses in lung transplant patients and healthy control subjects without lung disease will be compared over the course of the 2008 to 2009 influenza season.
Serum collected from participants before immunization, 2 to 4 weeks after immunization (postimmunization), and 6 months after immunization.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Receiving care post-lung transplant at University of Wisconsin Hospital
- •Healthy adult
排除标准
- •Allergy to eggs
- •Moderate to severe febrile illness
- •Active treatment for acute rejection
- •Received season's influenza vaccine prior to enrollment
研究组 & 干预措施
Vaccine, Post-transplant
Cohort consist of individuals who have received lung transplants Inactivated influenza vaccine will be administered intramuscularly annually.
干预措施: Influenza vaccine (Drug)
Vaccine, Healthy Control
Cohort consists of healthy individuals who received the influenza vaccine Inactivated influenza vaccine will be administered intramuscularly annually.
干预措施: Influenza vaccine (Drug)
结局指标
主要结局
Number of Participants with Seroprotection to Influenza Vaccine: 40 HAU
时间窗: up to 6 months
The hypothesis is that seroprotection, defined as 40 HAU or greater, will persist up to 6 months at high rates in lung transplant patients and that these rates will be comparable to the rates in healthy individuals. Seroprotection (antibody titer greater than or equal to 1:40) will be reported for H1N1, H3N2, and B viral antigens.
次要结局
- Number of Participants with Seroprotection to Influenza Vaccine: 160 HAU(up to 6 months)