Production and Testing of VLP-based RSV Vaccine

项目总结 这项SBIR第一阶段提案的目标是推动安全有效的类病毒的开发 以颗粒(VLP)为基础的呼吸道合胞病毒(RSV)疫苗预防由此引起的疾病 病原体。呼吸道合胞病毒在婴儿、儿童和老年人中引发的呼吸道疾病是全球性的 对经济和公共健康的影响。最近的一项全球估计[1，2]表明，超过3300万 5岁以下儿童患有呼吸道合胞病毒相关性下呼吸道感染(ALRI)，至少3岁 每年有100万人住院，约有19.9万人死于这种疾病。在美国，疾控中心 估计有超过12.6万人因呼吸道合胞病毒感染而住院，费用超过900美元 每年百万美元。目前还没有获得许可的疫苗，这种疾病的治疗也是有限的；a 预防性干预依赖于给婴儿注射中和单抗(Synagis®) 面临感染风险和支持性护理。一种安全有效的疫苗将是最可取的 成本效益高的预防性干预措施。然而，到目前为止，这种疫苗的研制还没有 福尔马林引起的疾病的增加阻碍了它的发展- 呼吸道合胞病毒灭活疫苗(FI-RSV)生产于20世纪60年代的S。其他方法尚未得到证实 成功的，甚至危险的。 在这里，我们建议进一步推进显示RSV抗原的病毒样颗粒的开发 一种创造安全有效的RSV疫苗的战略。我们的VLP方法显示了两种替代方案 F蛋白的构象，这是一种与其他疫苗不同的新策略 发展。RSVLP疫苗免疫原性、有效性和安全性的初步研究 在研究策略部分总结表明，这种疫苗具有高度的免疫原性，能够 提供针对病毒攻击的完全保护，而不会出现福尔马林的不良反应 呼吸道合胞病毒灭活疫苗对照[6]。VLP是野生型病毒颗粒的模拟物，但 不含病毒遗传物质，使它们不能复制或引起感染。颗粒物 VLP表面天然抗原的性质和冗余阵列激发了更大的认知力 免疫系统。我们已经成功地生产出显示F表面尖峰的RSV-VLP 蛋白质有两种不同的构象，融合前和融合后。用这些物质制成的疫苗 颗粒和在RSV小鼠模型中的测试表明，该颗粒具有高度的免疫原性，有效和 安全[6]。在这项申请中，我们建议继续开发这种疫苗，执行 在第二个动物模型棉花鼠中进行额外的临床前测试，以选择候选的 在人体上进行临床试验的进一步发展。为了实现这些目标，我们设计了三个 具体目标： 具体目标1-1-4个月： 生产、纯化和充分鉴定RSVLP疫苗组合物，该组合物含有预融合和 融合后F也可与G、SH或两者同时使用。确定适合的下游净化策略 用于未来cGMP生产的放大和工艺验证。 具体目标2-4-11： 评估免疫反应的大小和安全性，以及评估保护性 在RSV感染的棉鼠模型(S.hispidus)中，替代疫苗组合物提供的有效性。 具体目标3个月11-12年： 根据免疫学特征、保护效果和安全性选择最佳RSVLP疫苗成分 用于第二阶段SBIR应用的进一步疫苗开发研究。 成功完成拟议的研究将产生必要的数据，以保证进一步 第二阶段SBIR应用程序的开发。迫切需要一种RSV疫苗，该项目旨在 提出一种独特的疫苗组合物，可以考虑到其缺乏传染性和 针对几个人口结构的安全特征，如孕妇、幼儿和 老年人。

PROJECT SUMMARY The goal of this SBIR phase I proposal is to advance the development of a safe and efficacious virus-like particle (VLP) based-respiratory syncytial virus (RSV) vaccine to prevent the disease caused by this pathogen. The respiratory illnesses provoked by RSV in infants, children and the elderly are of global economical and public health impact. A recent worldwide estimate [1,2] indicates that over 33 million children under the age of five suffer RSV associated lower respiratory infections (ALRI) and at least 3 million are hospitalized and approximately 199,000 die of the disease each year. In the US, the CDC estimates that there are over 126,000 RSV associated pediatric hospitalizations at a cost of over $900 million per year. There is no vaccine currently licensed and treatments for the disease are limited; a prophylactic intervention relies on administering a neutralizing monoclonal antibody (Synagis®) to infants at risk of infection and to supportive care. A safe and effective vaccine would be the most desirable and cost effective preventive intervention. However, to date the creation of such a vaccine has not been attained and its development has been hindered by the enhancement of disease provoked by a formalin- inactivated RSV virus (FI-RSV) vaccine produced in the 1960’s. Other approaches have not proven successful and even dangerous. Here, we propose to further advance the development of a virus-like particle displaying RSV antigens as a strategy to create a safe and effective RSV vaccine. Our VLP approach displays two alternative conformation of the F protein, which is a novel and distinct strategy from other vaccine under development. Preliminary work on the immunogenicity, efficacy and safety of the RSVLP vaccine and summarized in the research strategy section showed that this vaccine is highly immunogenic and able to afford complete protection against virus challenge without the adverse reactions seen with a formalin inactivated RSV virus (FI-RSV) vaccine control [6]. VLPs are mimics of wild type virus particles but do not contain viral genetic material making them unable to replicate or cause infection. The particulate nature and redundant array of native antigen on the surface of the VLP incites a greater recognition by the immune system. We have successfully produced RSV-VLPs that display surface spikes of the F protein in its two different conformation, prefusion and postfusion. Vaccines formulated with these particles and tested in murine model of RSV demonstrated to be highly immunogenic, efficacious and safe [6]. In this application, we propose to continue the development of this vaccine performing additional preclinical testing in a second animal model, cotton rat, in order to select a candidate for further development toward clinical trials in humans. To fulfill these goals, we have designed three specific aims: Specific Aim 1- Months 1-4: Produce, purify and fully characterize RSVLP vaccine compositions containing the prefusion and postfusion F also in combination with G, SH or both. Define downstream purification strategies suitable for scale up and process validation for future cGMP manufacturing. Specific Aim 2- Months 4-11: Evaluate the magnitudes of the immune response and safety profile as well as appraise the protective efficacy afforded by alternative vaccine compositions in a cotton rat model (S. hispidus) of RSV infection. Specific Aim 3-Months 11-12: Select best RSVLP vaccine composition based on immunological profile, protective efficacy and safety for further vaccine development studies in a phase II SBIR application. Successful completion of proposed studies will generate the data necessary to warrant further development in a phase II SBIR application. An RSV vaccine is greatly needed and this project aims to advance a unique vaccine composition, which can be developed considering its lack of infectivity and safety characteristics toward several demographics such as pregnant women, young children and the elderly.