Production and Testing of VLP-based RSV Vaccine

项目摘要 SBIR第一阶段提案的目标是促进安全有效的病毒样药物的开发， 颗粒（VLP）为基础的呼吸道合胞病毒（RSV）疫苗，以防止这种疾病引起的 病原体RSV在婴儿、儿童和老年人中引起的呼吸道疾病是全球性的。 经济和公共卫生影响。最近的一项全球估计[1，2]表明， 5岁以下的儿童患有RSV相关的下呼吸道感染（ALRI）， 每年约有199，000人住院治疗，约有199，000人死于该病。在美国，CDC 估计有超过126，000例RSV相关的儿科住院治疗，费用超过900美元 每年百万。目前没有获得许可的疫苗，对这种疾病的治疗有限; 预防性干预依赖于对婴儿施用中和单克隆抗体（Synagis®） 有感染的风险，需要支持性治疗一种安全有效的疫苗将是最可取的， 具有成本效益的预防性干预措施。然而，到目前为止，这种疫苗的创造还没有被证实。 它的发展受到福尔马林引起的疾病的增强的阻碍， 灭活的RSV病毒（FI-RSV）疫苗在20世纪60年代生产。其他方法尚未证明 成功，甚至危险。 在此，我们建议进一步推进展示RSV抗原的病毒样颗粒的开发， 一种安全有效的RSV疫苗。我们的VLP方法显示了两种选择 F蛋白的构象，这是一种新的和独特的战略，从其他疫苗下， 发展RSVLP疫苗免疫原性、有效性和安全性的初步工作， 研究策略部分总结的结果表明，这种疫苗具有高度免疫原性， 对病毒攻击提供完全保护，而没有福尔马林所见的不良反应 灭活RSV病毒（FI-RSV）疫苗控制[6]。VLP是野生型病毒颗粒的模拟物，但 不含病毒遗传物质，使它们无法复制或引起感染。颗粒 VLP表面上天然抗原的性质和冗余阵列激发了更大的识别， 免疫系统.我们已经成功地生产了RSV-VLP，显示F的表面尖峰， 蛋白质在融合前和融合后两种不同的构象。用这些配制的疫苗 颗粒并在RSV的鼠模型中测试，证明是高度免疫原性的、有效的和 安全[6]。在本申请中，我们建议继续开发这种疫苗， 在第二种动物模型棉鼠中进行额外的临床前试验，以选择用于 进一步发展为人类临床试验。为了实现这些目标，我们设计了三个 具体目标： 具体目标1-第1-4个月： 生产、纯化和充分表征含有融合前和融合后的RSVLP疫苗组合物。 融合后F也与G、SH或两者组合。确定合适的下游纯化策略 用于未来cGMP生产的规模放大和工艺验证。 具体目标2个月4-11： 评价免疫应答的程度和安全性特征，并评估保护性 在棉鼠模型中由替代疫苗组合物提供的功效（S. hispidus）的RSV感染。 具体目标3个月11-12： 根据免疫学特征、保护效力和安全性选择最佳RSVLP疫苗组合物 在第二阶段SBIR应用中进行进一步的疫苗开发研究。 成功完成拟议的研究将产生必要的数据， 在第二阶段SBIR应用中的开发。非常需要RSV疫苗，该项目旨在 提出一种独特的疫苗组合物，考虑到其缺乏感染性， 安全性特征对几个人口统计学，如孕妇，幼儿和 老人

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.