Pneumococcal Conjugate Vaccine Followup: Investigation of Serotype-specific Antibody Persistence and B Cell Memory at Age 3-5 Years Following 23valent Pneumococcal Polysaccharide Vaccine at Age 9 Months in PNG Children Previously Primed With 7valent Pneumococcal Conjugate Vaccine
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 发起方
- 入组人数
- 280
- 试验地点
- 2
- 主要终点
- Measure serotype-specific antibody persistence in children aged 3-5 years after vaccination with 23vPPV at 9 months of age and compared to unvaccinated controls.
研究概览
简要总结
Recently, controversy has emerged regarding the role of the 23vPPV in infants due to potential immunological hypo-responsiveness (i.e. a poorer immune response to repeat vaccination). Although previous experience of 23vPPV in children in PNG has demonstrated protective efficacy against acute lower respiratory tract infection, the investigators feel it is a matter of urgency to determine if 23vPPV administration provides elevated antibody concentrations at 3 to 5 years of age, and to ensure the immunological safety of the 23vPPV in infants.
Following consent and eligibility assessment, a baseline blood sample and nose swab will be taken, a 0.1ml dose of 23vPPV will be administered and a follow up blood sample and nose swab will be collected 28 days later. The investigators will also collect data on incidence of ALRI in all study participants by medical record review.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 3 Years 至 5 Years（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •PNG Infants aged 3 to 5 yrs of age who participated in previous PNG Neonatal PCV study and received PPV between 9 and 12 months of age, or age- and sex-matched controls who live in the same villages or urban area
- •Informed parental/guardian consent
排除标准
- •Known HIV infection or other immunosuppressive condition or treatment.
- •Prior receipt of 2 doses of pneumococcal polysaccharide vaccine
结局指标
主要结局
Measure serotype-specific antibody persistence in children aged 3-5 years after vaccination with 23vPPV at 9 months of age and compared to unvaccinated controls.
时间窗: 2yrs
Children who were previously vaccinated with Pneumovax (23vPPV) at 9 months will be followed up at age 3-5 years of age. They will be given a challenge dose of Pneumovax (0.1mL) and followed up 1 months later. Age matched controls identified from each villages will also be recruited and given a challenge dose of Pneumovax. Serotype-specific antibodies will be measure pre- and post-challenge dose to determine anitbody levels.
次要结局
- Measure the number of circulating serotype-specific memory B-cells pre- & post- booster immunisation(2yrs)
- Measure nasopharyngeal pneumococcal serotype-specific carriage rates pre- and post- 23vPPV challenge dose(2yrs)
研究者
William Pomat
Senior Research Fellow
Papua New Guinea Institute of Medical Research