Development of Influenza Virus-Like Particle (VLP) Vaccines

描述(申请人提供)：流感病毒样颗粒(VLP)在临床前研究中证明，它们具有高度的免疫原性，在预防流感感染方面有效。这种新兴的疫苗技术不仅创造了具有替代给药途径(鼻内或肌肉内)的新候选疫苗，而且还实施了一种快速、灵活和可靠的基于细胞的制造系统，该系统克服了与当前鸡蛋生产系统相关的许多负担。VLP是一种在形态和生物化学上模仿野生型流感病毒的结构，但它们缺乏病毒遗传物质，无法复制并导致感染；因此不需要化学灭活。这更好地保持了VLP疫苗中抗原表位的天然构象。这项技术的安全性允许开发针对高致病性流感病毒株的疫苗，而不会有传播传染性物质的风险。第一阶段SBIR奖使我们能够在临床前研究中创建和测试几种VLP候选疫苗，这些候选疫苗旨在预防H1N1-1918、H5N1和H7N7禽流感病毒等高致病性大流行流感病毒株。这些研究表明，VLP疫苗具有免疫原性和有效性，进一步证明了VLP技术在流感疫苗开发中的价值。在目前的应用中，我们建议通过更多的临床前研究来进一步推进这些疫苗产品的开发。在cGMP生产之前，我们将开发一个大规模生产VLP疫苗的纯化系统。我们将在昆虫细胞/杆状病毒系统生产的VLP疫苗和稳定转基因的重组哺乳动物细胞生产的相同VLP疫苗之间进行一项比较初步研究。此外，我们的目标是与FDA一起为创新前药物应用(IND)进行小规模cGMP疫苗生产和毒理学研究。SBIR第二阶段的具体目标是：a)生产、鉴定和在小鼠临床前研究中测试旨在预防1)H5N1禽流感病毒、2)人H1N1-1918流感病毒和3)H7N7禽流感的流感病毒样颗粒疫苗，进行交叉保护和提高免疫原性(包括老年人)研究以及开发一种大规模的纯化方法，比较由昆虫细胞/杆状病毒系统生产的H5N1 VLP疫苗和由最近开发的稳定转化的哺乳动物生产的相同疫苗的免疫原性，该系统可被开发为第二代VLP制造系统。B)在雪貂的临床前研究中，评估疫苗的效力、剂量和佐剂配方，以提高疫苗效力和节省抗原。C)与FDA一起为创新前药物申请(IND)进行小规模cGMP疫苗生产和毒理学研究。SBIR第二阶段的完成将使VLP疫苗技术达到在人体上进行第一阶段临床试验的地步，并将推动这种新的疫苗产品和制造系统走向商业化。尽管在本项目期间正在开发大流行性流感VLP疫苗，但结果将验证季节性流感疫苗开发技术的稳健性，目前VLP技术存在生产时间延长、对鸡蛋的依赖、某些毒株的产量不足、适应新出现的变种缺乏灵活性以及在处理高毒力病毒时不适合的问题，所有这些都是VLP技术优越的问题。SBIR第二阶段将加速开发重要的预防性疫苗(例如H5、H7禽流感和1918)，并将验证用于生产流行性流感疫苗的更快、更灵活、基于细胞的技术。与公共卫生相关：流感是一种反复发作的呼吸道感染，困扰着世界各地的人类。病毒不断变化，产生新的流行和大流行病毒，需要疫苗。尽管有针对流行毒株的预防性疫苗可用，但需要定期更新以维持保护效力。大流行病毒疫苗匮乏，研制疫苗至关重要。在此，我们建议进一步开发流感病毒样颗粒(VLP)技术，用于生产大流行和流行性流感疫苗。这项技术是快速、灵活和可靠的，可以制造在细胞系统中生产的高效疫苗。VLP疫苗系统克服了鸡蛋生产系统的许多问题。这些疫苗的成功开发将造福全球社会。

DESCRIPTION (provided by applicant): Influenza virus-like particles (VLPs) have demonstrated in preclinical studies that they are highly immunogenic and efficacious in protecting against influenza infections. This emerging vaccine technology not only creates new vaccine candidates with alternative routes of administration (intranasal or intramuscular) but also implements a fast, flexible, and dependable cell-based manufacturing system that overcomes many of the burdens associated with the current egg production system. VLPs are structures that morphologically and biochemically mimic a wild type influenza virus, however they lack viral genetic material and are unable to replicate and cause infection; therefore chemical inactivation is not required. This better maintains the native conformation of the antigenic epitopes in the VLP vaccine. The safety of the technology allows for the development of vaccines directed against highly pathogenic influenza virus strains without the risk of disseminating infectious material. The Phase I SBIR award allowed us to create and test in preclinical studies several VLP vaccine candidates designed to protect against highly pathogenic pandemic strains of the influenza virus such as H1N1-1918; H5N1 and H7N7 avian influenza viruses. These studies have shown that VLP vaccines are immunogenic and efficacious, further proving the value of the VLP technology for influenza vaccine development. In the current application, we propose to further advance the development of these vaccine products with additional preclinical studies. We will develop a purification system for large scale manufacturing of VLP vaccines, prior to cGMP manufacturing. We will perform one comparative pilot study between a VLP vaccine produced in the insect cell/baculovirus system and the same VLP vaccine produced in stably transfected recombinant mammalian cells. Further, we aim to perform small scale cGMP vaccine production and toxicology studies for a Pre-Innovation Drug Application (IND) with the FDA. The specific aims of the Phase II SBIR are: A) To produce, characterize, and test in preclinical studies in mice the influenza-virus-like particle (VLP) vaccines designed to protect against 1) H5N1 avian influenza virus, 2) human H1N1-1918 influenza virus and 3) H7N7 avian influenza, and to perform cross protection and enhancement of immunogenicity (including in the elderly) studies as well as to develop a large scale purification method and to compare the immunogenicity of the H5N1 VLP vaccine produced in the insect cell/ baculovirus system and the same vaccine produced in a recently developed stably transformed mammalian which could be developed as a second generation VLP manufacturing system. B) To evaluate vaccine efficacy, dosage and adjuvant formulations for enhancement of vaccine potency and antigen sparing in preclinical studies in ferrets. C) Perform small scale cGMP vaccine production and toxicology studies for a Pre-Innovation Drug Application (IND) with the FDA. Completion of this SBIR Phase II will bring the VLP vaccine technology to the point of a Phase I clinical trial in humans and will advance this new vaccine product and manufacturing system towards commercialization. Although pandemic influenza VLP vaccines are being developed during this project, the outcome will validate the robustness of the technology for development of seasonal influenza vaccine which currently is burdened with prolonged production times, dependence on chicken eggs, insufficient yield with certain strains, inflexibility for accommodating newly emerging variants, and unsuitability when working with highly virulent virus, all issues where the VLP technology is superior. This SBIR Phase II will accelerate the creation of vital prophylactic vaccines (e.g. H5, H7 avian flu and 1918) and will also validate a faster, more flexible, cell-based technology for epidemic influenza vaccine production. PUBLIC HEALTH RELEVANCE: Influenza is a recurrent respiratory infection afflicting humans all over the world. The virus changes constantly generating new epidemic and pandemic viruses, for which vaccines are needed. Although prophylactic vaccines for epidemic strains are available, periodic updates are required to maintain protective efficacy. Vaccines for pandemic viruses are lacking and their development is critical. Here we proposed to further develop the influenza virus-like particle (VLP) technology for the generation of pandemic and epidemic influenza vaccines. This technology is fast, flexible, and reliable for creating highly effective vaccines which are manufactured in a cell-based system. The VLP vaccines system overcomes many of the problems of the egg production system. Successful development of these vaccines will benefit society globally.