Trivalent Lassa, Ebola and Marburg viral vaccine (Tri-LEMvac)

非洲出血热病毒对低收入国家和发展中经济体的人类健康有重大影响（Heeney，内科医学杂志，2006年）。拉沙热是西非的地方病，估计感染人数在30万至100万之间，每年有5000人死亡。它与埃博拉病毒（EBOV）等丝状病毒引起的其他病毒性出血热（vhf）重叠的地理分布，使2014/2015年西非疫情中埃博拉病毒病的早期临床诊断复杂化。旧大陆沙粒病毒和丝状病毒联合疫苗可对西非和中非最重要的出血热病毒拉沙热病毒（LASV）、埃博拉病毒（EBOV）和马尔堡病毒（MARV）产生保护作用，这将极大地有助于控制这些臭名昭著的病原体的传播。目前尚无针对这些感染的许可疫苗。非常需要一种单一疫苗来预防所有这三种具有区域重要性的甚高频病毒，这种疫苗经济、易于生产、易于部署并且在没有连续冷链储存的情况下温度稳定。改良安卡拉牛痘（MVA）疫苗平台是一种非复制株第三代天花疫苗，也是人类临床试验中最先进的重组痘病毒疫苗载体之一（Cottingham & Carroll, vaccine, 2013）。MVA是一个强大的载体系统，能够共表达多达四种转基因，促进有效的启动子和稳定的插入位点（Orubu等人，Pone, 2012）。我们将把EVAC和LassaVacc （Innovate UK）的协同新平台技术结合在一起。利用EVAC的DIOS合成免疫优化疫苗插入物，与LassaVacc的基于MVA的LASV （NP/GPC T和b细胞抗原）一起，提供尽可能广泛的疫苗保护，我们将开发一种单一的三价疫苗（Tri-LEMvac），该疫苗将产生联合疫苗效力，以应对未来爆发的出血热拉沙、埃博拉和马尔堡病毒变体。为了实现这一目标，我们提出了两个阶段：阶段1)概念验证（此应用程序）。在12个月内，我们将通过构建在单个MVA中表达保守的拉沙、埃博拉和马尔堡抗原插入物的三价MVA来证明概念的有效性，确认最佳表达，在小动物中展示免疫原性，并通过活病毒攻击这些病原体来证明有效性。MVA是一种经过临床试验的疫苗载体，我们将用它来比较免疫反应、保护广度、持久性和有效性的改善情况。这种新的三价LEMvac MVA疫苗将允许在第二阶段的头对头临床试验中进行直接比较。第二阶段)后续建议；完善临床前工作，包括GLP制造毒理学/制造。进行Tri-LEMvac的首次人体I期试验，以确定剂量、一次注射的持久性和安全性。

African haemorrhagic fever viruses have a significant impact on human health in low income countries and developing economies (Heeney, J Internal Med, 2006). Lassa fever is endemic to Western Africa with estimates ranging between 300,000 to a million infections, with 5,000 deaths per year. It’s overlapping geographic distribution with other Viral Haemorrhagic Fevers (VHFs) caused by Filoviruses such as Ebola virus (EBOV), complicated the early clinical diagnosis of Ebola virus disease in the 2014/2015 West African outbreak. A combined Old World Arenavirus and Filovirus vaccine eliciting protection against Lassa Fever virus (LASV), Ebola (EBOV) and Marburg (MARV) viruses, the most important haemorrhagic fevers in West and Central Africa, would be of great benefit in the control of spread of these notorious pathogens. Currently there are no licensed vaccines for these infections. A single vaccine to protect against all three of these regionally important VHFs that was economic, easy to produce, readily deployable and temperature stable in the absence of continuous cold chain storage would be highly desirable. The Modified Vaccinia Ankara (MVA) vaccine platform is a non-replicating strain third generation smallpox vaccine and one of the most advanced recombinant poxviral vaccine vectors in human clinical trials (Cottingham & Carroll, Vaccine, 2013). MVA is a robust vector system capable of co-expressing up to four transgenes facilitating potent promoters and stable insertion sites (Orubu et al, Pone, 2012). We will bring synergistic new platform technologies together from EVAC and LassaVacc (Innovate UK). Using EVAC’s DIOS synthetic immune optimised vaccine inserts to give the broadest possible vaccine protection, together with LassaVacc's MVA based LASV (NP/GPC T & B-cell antigens) we will develop a single trivalent vaccine (Tri-LEMvac) that will generate combined vaccine efficacy against future outbreaks of variants of the haemorrhagic fever Lassa, Ebola and Marburg viruses.Towards this goal we propose two stages: Stage 1) Proof of concept (this application). Within 12 months, we will demonstrate proof of concept by constructing trivalent MVAs expressing conserved Lassa, Ebola and Marburg antigen inserts in a single MVA, confirming optimal expression, demonstrating immunogenicity in small animals and efficacy by live virus challenges with these pathogens. MVA is a clinically trialled vaccine vector which we will use to compare improvements in immune responses, the breadth of protection, durability and efficacy. This new trivalent LEMvac MVA vaccine will allow direct comparison in head to head clinical trials in stage 2. Stage 2) follow-up proposal; refine preclinical work, including GLP manufacturing toxicology/manufacturing. To perform first in human phase I trials of Tri-LEMvac to establish dose, durability of one shot versus prime boost and safety.