Immune Responses to Vibrio cholerae infection and vaccination in Haiti

描述（由申请人提供）：海地正在发生的霍乱疫情是过去十年中规模最大的疫情之一，代表了霍乱疫情日益加重的负担。在免疫力低下的人群以及历史上霍乱流行地区以外的亚洲人群中，对霍乱和口服霍乱疫苗的免疫反应知之甚少。最重要的是，所有关于使用霍乱疫苗的决定都是根据世界上霍乱长期根深蒂固的地区的免疫原性和有效性数据作出的，在这些地区，霍乱疫苗可能会增强以前接触者的遗忘性免疫反应。因此，在海地Shanchol推广期间对疫苗免疫原性和有效性的评估为直接制定疫苗战略提供了独特的机会。尽管目前向世卫组织报告的最多霍乱病例来自撒哈拉以南非洲，但人们对艾滋病毒与霍乱之间的关系几乎一无所知。在这里，我们建议表征对口服霍乱疫苗和海地霍乱弧菌感染的免疫反应——海地以前免疫缺乏的人口具有宿主和流行病学特征，反映了近年来经历霍乱流行的人口。我们还直接评估了海地口服霍乱疫苗Shanchol的疗效，并评估了艾滋病毒和霍乱弧菌感染与疫苗接种之间的相互关系。我们的合作团队深入参与了海地霍乱疫苗的推广工作，具有开展拟议研究的独特条件。

DESCRIPTION (provided by applicant): The ongoing epidemic of cholera in Haiti is one of the largest of the last decade and is representative of a growing burden of epidemic cholera. Remarkably little is known about immune responses to cholera and oral cholera vaccines in immunologically na¿ve populations, and in populations outside of historically cholera endemic areas of Asia. Of paramount importance, all decisions regarding the use of cholera vaccine have been made using immunogenicity and efficacy data generated in areas of the world where cholera has long been entrenched and where cholera vaccine may be boosting anamnestic immune responses in previously exposed individuals. Therefore, assessment of vaccine immunogenicity and effectiveness during the roll out of Shanchol in Haiti provides the unique opportunity to directly inform vaccine strategies. Almost nothing is known about the relationship between HIV and cholera, despite the fact that the largest number of cholera cases reported to WHO are now from Sub-Saharan Africa. Here, we propose to characterize immune responses to oral cholera vaccines and to V. cholerae infection in Haiti -- a previously immunologically na¿ve population with host and epidemiologic features that are reflective of populations experiencing cholera epidemics in recent years. We also directly assess the efficacy of the oral cholera vaccine, Shanchol, in Haiti, and evaluate the inter-relationship between HIV and V. cholerae infection and vaccination. Our collaborative team is deeply involved in the cholera vaccine roll-out in Haiti and is uniquely situated to perform the proposed studies.