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

“疫苗是对抗传染病的关键武器，传染病继续对低收入国家的健康和发展产生重大有害影响。然而，一些疫苗在热带LIC以及在农村和城市环境中的效力会降低。例如，结核病疫苗卡介苗在一些温带国家提供80%的保护，但在一些热带地区提供0%的保护。这种现象的潜在解释包括接触寄生虫，因此为了进一步了解，我们将比较三组乌干达青少年对疫苗的反应：(1)参与我们恩德培母婴研究的城市居民，他们的出生队列中寄生虫暴露的比例很低；(2)岛屿社区，超过80%的人感染了血吸虫病(一种寄生虫感染)；(3)农村社区，超过50%的学童在不知不觉中感染了疟疾。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)，以及这些间接影响如何影响免疫系统。最后，我们将使用统计学方法来探索城乡环境、寄生虫、“跨王国”效应和免疫反应如何相互关联来确定疫苗反应。这些基本信息将有助于为生活在热带LIC环境中的人口开发合适的疫苗，并为公共卫生政策提供信息，以提高疫苗计划的有效性。“

"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."