The Effect of Fractional Doses of Pneumococcal Conjugate Vaccines on Immunogenicity and Carriage in Kenyan Infants

Before the introduction of pneumonia vaccines in 2000, between 700,000 - 1 million children died each year as a result of infection with the bacteria Streptococcus pneumoniae and the resulting diseases, namely, meningitis, sepsis and pneumonia. Most of the deaths were in Africa and Asia. Where the vaccines have been introduced, they have been highly effective and have already reduced disease. However, at 10 USD per child, they are not affordable to most low-income countries without financial support from Gavi, the Vaccine Alliance. This project aims to assess whether lower doses of the two commercially available pneumonia vaccines can protect Kenyan infants as well as the full dose. The results could be used to increase the affordability of the pneumonia vaccine, and enable delivery of the vaccine to continue in the absence of Gavi support. The trial is registered on ClinicalTrials.gov - NCT03489018 This data package includes: Study Protocol

2000年肺炎疫苗推广应用前，每年有70万至100万名儿童因感染肺炎链球菌（Streptococcus pneumoniae）及其引发的脑膜炎、败血症与肺炎死亡，其中绝大多数死亡病例集中在非洲与亚洲地区。
尽管该疫苗在已推广地区展现出极高的防护效力，有效降低了相关疾病的发病率，但每剂10美元的定价，使得大多数低收入国家在无法获得全球疫苗免疫联盟（Gavi, the Vaccine Alliance）的资金支持时，难以负担该疫苗的接种成本。
本项目旨在评估两款已上市的肺炎疫苗采用低剂量接种时，能否为肯尼亚婴儿提供与全剂量接种等效的保护效果。研究结果有望提升肺炎疫苗的可负担性，并帮助相关地区在缺乏该联盟资金支持的情况下仍能持续推进疫苗接种工作。
本临床试验已在ClinicalTrials.gov平台注册，注册编号为NCT03489018。
本数据包包含以下内容：研究方案（Study Protocol）。