Population differences in vaccine response (POPVAC)-2: the impact of environmental exposures and selected interventions on waning of vaccine-induced immune responses

“疫苗是预防传染病的关键武器，传染病继续对低收入国家的健康和发展产生重大不利影响。然而，一些疫苗在热带低收入国家和农村与城市环境中的有效性有所降低。例如，结核病疫苗卡介苗在一些温带国家提供80%的保护，但在一些热带国家提供0%的保护。对这一现象的一个潜在解释包括接触寄生虫，因此为了进一步了解，我们将比较乌干达青少年在三组中的疫苗反应：(1)参加我们的恩德培母婴研究出生队列的城市居民，他们的寄生虫接触率低；(2) 80%以上血吸虫病（一种寄生虫感染）的岛屿社区；(3)疟疾暴露率高的农村社区，超过50%的学龄儿童在不知情的情况下感染了疟疾。我们还将研究寄生虫感染如何与其他病毒或细菌感染相互作用（“跨王国”效应），以及这些间接效应如何影响免疫系统。最后，我们将使用统计方法来探讨城乡环境、寄生虫、“跨王国”效应和免疫反应如何相互关联，以确定疫苗反应。这一基本信息将有助于为生活在热带低收入国家的人口开发合适的疫苗，并为公共卫生政策提供信息，以提高疫苗规划的有效性。”

"Vaccines are a key weapon against infectious diseases which continue to have major detrimental impacts on health and development in in low-income countries (LICs). However, the effectiveness of some vaccines is reduced in tropical LICs and in rural vs urban settings. For example, the TB vaccine, BCG, provides 80% protection in some temperate countries, but 0% in some tropical settings. A potential explanation for this phenomena includes exposure to parasites so to further understanding we will compare the vaccine responses for Ugandan adolescents among three groups: (1) urban-dwellers participating in our Entebbe Mother and Baby Study birth cohort who have low parasite exposure; (2) island communities where over 80% have schistosomiasis (a parasitic worm infection); (3) rural communities with high malaria exposure, where over 50% of school-children unknowingly have malaria. We will also look at how parasitic infections interact with other viral or bacterial infections (“transkingdom” effects) and how these indirect effects impact the immune system. Finally, we will use statistical approaches to explore how the urban-rural environment, parasites, ""transkingdom"" effects and immune responses interrelate to determine vaccine responses. This fundamental information will contribute to the development of suitable vaccines for populations living in tropical LIC settings and inform public health policy to improve effectiveness of vaccine programmes."