A study to investigate alternative regimens for pneumococcal vaccination of infants in a developing country

肺炎链球菌(PNC)是导致婴儿严重感染的主要疫苗可预防原因。目前的PNC结合疫苗非常昂贵(婴儿约200美元)，因此大多数发展中国家不太可能负担得起。此外，由于发展中国家获得卫生保健的机会可能是间歇性的和不可靠的，许多儿童没有接受完整或及时的疫苗课程。因此，重要的是要研究负担得起的、灵活的、安全有效的疫苗接种方式。世卫组织-全球疫苗和免疫联盟最近举行了一次会议，以解决在发展中国家采用这些疫苗的障碍，会议认识到有必要评估其他方案的PNC结合疫苗，作为一项重要的研究优先事项。这项研究是在考虑到这一需求的情况下特意制定的。这项研究的地点是斐济。虽然卫生服务很好，但PNC疾病，特别是肺炎，仍然是儿童发病率和死亡率的最常见原因。斐济的疫苗覆盖率很高，是第一个引进Hib疫苗的太平洋国家。新的昂贵的PNC结合疫苗的到来给斐济和许多类似的国家带来了两难境地。这种疫苗的费用将消耗卫生预算的很大一部分。这项研究包括两个组成部分：1.第二阶段免疫原性研究(涉及750名婴儿)，以评估使用减少剂量的PNC结合疫苗的方案，以及使用可能更适合发展中国家PNC疾病流行病学的PNC多糖疫苗的给药时机和组合。2.一项流行病学研究将衡量斐济侵袭性肺炎和肺炎的负担。这将是解决这些问题的全球努力的一部分，并将用于在发展中国家开发这些疾病的快速评估工具。我们将寻求这一组成部分的共同创立。

Streptococcus pneumoniae (Pnc) is the leading vaccine preventable cause of serious infection in infants. The current Pnc conjugate vaccine is very expensive (approximately USD $200-infant) so it is unlikely to be affordable for most developing countries. Moreover, as health care access in developing countries may be episodic and unreliable, many children do not receive either complete or timely vaccine courses. Therefore, it is important to investigate affordable and flexible ways to deliver this vaccine, which are safe and effective. A recent WHO-GAVI meeting to address impediments to the introduction of these vaccines in developing countries recognized the need to evaluate other regimens of Pnc conjugate vaccine as an important research priority. This study has been deliberately formulated with that need in mind. The site for this research is Fiji. Although health services are good, Pnc disease, particularly pneumonia, remains the commonest cause of childhood morbidity and mortality. Fiji has good vaccine coverage and was the first Pacific country to introduce Hib vaccine. The arrival of the new, expensive Pnc conjugate vaccine presents a dilemma for Fiji and many similar countries. The expense of this vaccine would consume a large portion of the health budget. This study has two components: 1. A Phase 2 immunogenicity study (involving 750 infants) to evaluate regimens using reduced numbers of doses of Pnc conjugate vaccine, and using timing of dosing and combinations with the Pnc polysaccharide (PS) vaccine that may be more suited to the epidemiology of Pnc disease in developing countries. 2. An epidemiological study will measure the burden of invasive Pnc disease and pneumonia in Fiji. This will be part of a global effort to address these issues, and will be used to develop rapid assessment tools for these diseases in developing countries. We will seek cofounding for this component.