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、败血症与肺炎而死亡，此类死亡病例绝大多数分布于非洲与亚洲地区。在已推广使用该疫苗的地区，其保护效力显著，已有效降低了相关疾病的发病负担。然而单剂定价为10美元的该疫苗，在无法获得疫苗联盟（Gavi, the Vaccine Alliance）资金支持的情况下，大多数低收入国家难以负担其采购成本。本项目旨在评估两款已上市的肺炎疫苗，采用降低剂量的接种方案，是否能为肯尼亚婴儿提供与全剂量接种相当的保护效果。本研究结果或可提升肺炎疫苗的可及性，并助力在缺乏Gavi资助的情况下持续推进疫苗接种工作。本临床试验已在ClinicalTrials.gov注册，注册编号为NCT03489018。本数据包包含以下内容：研究方案（Study Protocol）