Broadly Specific Needle-Free Vaccines against Emerging and Biothreat Viruses

描述（由申请方提供）：针对丝状病毒埃博拉（EBOV）和马尔堡（MARV）的疫苗开发受到这些病毒的多个种属和毒株（包括无抗原相关性或抗原相关性有限的病毒）同时传播的阻碍。目前正在开发的候选疫苗包括GP蛋白作为丝状病毒的主要保护性抗原。这些候选人都有严重的局限性。这些因素包括需要非常高或多剂量的保护、在载体特异性抗体存在下缺乏免疫原性、载体的潜在毒性、生产成本高以及缺乏无针施用的可行技术。此外，最重要的 现有候选疫苗的局限性在于，它们都需要多种组分来保护免受单个丝状病毒物种的侵害，并且它们对目前未鉴定的物种或菌株的保护水平不清楚，所述物种或菌株将在未来出现并且与已知物种具有有限的抗原相关性。我们先前的数据表明，用基于表达EBOV GP的减毒呼吸道副粘病毒的载体对豚鼠和非人灵长类动物（NHP）进行粘膜呼吸道免疫接种诱导了强有力的血清EBOV中和抗体应答;赋予动物针对用高致死剂量的EBOV的腹膜内攻击的“杀菌”免疫;并诱导呼吸道中的粘膜抗体应答。针对H5 N1高致病性禽流感病毒的单组分疫苗开发的最近突破性方法是基于来自多种病毒的共有、祖先或计算优化的广泛反应性抗原（COBRA）序列的产生，其赋予针对病毒的多个不同进化枝的保护，而没有或有限的抗原相关性。此外，过去对流感病毒的研究表明，流感疫苗的粘膜而非胃肠外递送诱导交叉反应性粘膜IgG和伊加以及血清IgG，以及针对抗原性不同的异亚型流感病毒的B细胞依赖性保护。该提案包括开发一种广泛特异性的泛丝状病毒疫苗，该疫苗基于EBOV和MARV的祖先、共有或COBRA GP蛋白，由减毒的呼吸道副粘病毒表达，其保护范围将通过其通过呼吸道粘膜给药进一步增强，并且其将对目前传播的所有丝状病毒以及将来传播的丝状病毒具有保护性。具体 目标如下：（1）开发和测试能够通过衍生两种病毒中的每一种的祖先、共有或COBRA GP蛋白来诱导针对EBOV或MARV的多价应答的单一疫苗组分;（2）提高疫苗的免疫原性和保护效力，并且通过选择最有效的载体变体和优化剂量和疫苗接种方案来最小化诱导保护性免疫应答所需的时间;（3）分析对免疫接种的全身和局部免疫应答，以确定用于临床试验的有效保护相关性。

DESCRIPTION (provided by applicant): Development of a vaccine against the filoviruses Ebola (EBOV) and Marburg (MARV) is hindered by the simultaneous circulation of multiple species and strains of these viruses, including those with no or limited antigenic relatedness. Vaccine candidates currently in development include the GP protein as the major protective antigen of filoviruses. Each of these candidates has severe limitations. These include the need for very high or multiple doses for protection, the lack of immunogenicity in the presence of vector-specific antibodies, the potential virulence of vectors, high cost of production, and the lack of feasible technologies for their needle-free administration. In addition, the most important limitations of the existing vaccine candidates is that they all require multiple components to protect against individual species of filoviruses, and their unclear level of protection against currently unidentified species or strains which will appear in the future and have a limited antigenic relatedness to the known species. Our previous data demonstrate that mucosal respiratory tract immunization of guinea pigs and non-human primates (NHP) with vectors based on attenuated respiratory paramyxoviruses expressing EBOV GP induces a robust serum EBOV-neutralizing antibody response; confers to the animals "sterilizing" immunity against intraperitoneal challenge with a highly lethal dose of EBOV; and induces mucosal antibody response in the respiratory tract. Recent breakthrough approaches for development of single-component vaccines against the H5N1 highly pathogenic avian influenza viruses were based on the generation of consensus, ancestral or Computationally-Optimized Broadly Reactive Antigen (COBRA) sequences derived from multiple viruses, which conferred protection against multiple diverse clades of the virus with no or limited antigenic relatedness. Moreover, a past study with influenza virus demonstrated that a mucosal, but not parenteral delivery of an influenza vaccine induced cross-reactive mucosal IgG and IgA and serum IgG, and B-cell dependent protection against antigenically different heterosubtypic influenza viruses. The proposal includes development of a broadly specific, pan-filovirus vaccine based on ancestral, consensus, or COBRA GP proteins of EBOV and MARV, expressed by attenuated respiratory paramyxoviruses, whose breadth of protection will be further enhanced by their mucosal administration through the respiratory tract, and which will be protective against all filoviruses that circulate at the present time as well as those that will circulate in the future. The Specific Aims are the following: (1) Develop and test single vaccine components capable of inducing multivalent responses against EBOV or MARV by deriving ancestral, consensus, or COBRA GP proteins for each of the two viruses; (2) Improve immunogenicity and protective efficacy of the vaccine, and minimize time required for induction of the protective immune response by selecting the most potent vector variants and optimizing dosage and the vaccination regimen; (3) Analyze the systemic and local immune responses to immunizations to determine valid correlates of protection for clinical trials.