Developing a Thermostable SARS-CoV-2 RBD-particle Vaccine

项目总结 严重急性呼吸系统综合症引发的冠状病毒病2019年(新冠肺炎)全球大流行 冠状病毒2(SARS-CoV-2)是我们一生中从未有过的，已经造成了重大的社会、经济和 人类的苦难。全球共有76,858,506例确诊病例，导致1,711,498人死亡 由世界卫生组织报告，截至2020年12月。美国食品和药物管理局授权的辉瑞(-80˚C存储)和 现代(-20˚C储存)疫苗强调了低必需储存温度带来的挑战。 消除对新出现的疫苗解决方案的冷链要求可以促进分销并提供 可观的供应链成本节约。为了克服冷链需求，POP生物技术公司提出了 探索其新型疫苗佐剂平台诱导自发抗原的冷冻干燥策略 颗粒，使用SARS冠状病毒-2刺突蛋白(S)的受体结合结构域。我们是世界上 首先证明一种液体形式的RBD颗粒按顺序有效地增加SARS-CoV-2中和抗体 与可溶性抗原相比具有重要的意义。我们的疫苗平台诱导井下的颗粒形成- 通过简单地与含有少量钴的脂质体混合来表征His标记的抗原 卟啉磷脂(CoPoP)和临床佐剂单磷脂A和QS-21。CoPoP 脂质体能迅速形成在生物介质中稳定的抗原颗粒化。在此协作阶段I SBIR建议，我们将评估冷冻干燥对蛋白质构象和热稳定性的影响 生产的冻干疫苗，通过生化和生物物理测试进行评估，并对其效果进行评估 通过在小鼠中的功能免疫原性。该项目将评估打破冷链的可行性 对下一代粒子疫苗系统的要求，这对于资源有限的环境可能是至关重要的。 在与德克萨斯生物医学研究所(TBRI)的合作下，一种针对SARS冠状病毒的转基因小鼠模型- 2感染将用于研究冻干RBD颗粒疫苗对保护作用的热稳定性。 1

PROJECT SUMMARY The coronavirus disease 2019 (COVID-19) global pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is unprecedented in our lifetime and has caused major social, economic and human suffering. Globally, there have been 76,858,506 confirmed cases, leading to 1,711,498 deaths as reported by the WHO through December 2020. The rollout of FDA-authorized Pfizer (-80 ˚C storage) and Moderna (-20 ˚C storage) vaccines has highlighted the challenges posed by low requisite storage temperatures. Elimination of cold chain requirements for emerging vaccine solutions could facilitate distribution and provide considerable supply chain cost savings. To overcome cold chain requirements, POP Biotechnologies proposes to investigate a lyophilization strategy for its novel vaccine adjuvant platform that induces spontaneous antigen particles, using the receptor-binding domain (RBD) of the SARS CoV-2 spike (S) protein. We were amongst the first to show that a liquid form of RBD particles potently increases SARS-CoV-2 neutralizing antibodies by orders of magnitude compared to the soluble antigen. Our vaccine platform induces the particle formation of well- characterized his-tagged antigens by simple admixing with liposomes that contain small amounts of cobalt porphyrin-phospholipid (CoPoP) and the clinical adjuvants monophosphoryl lipid A and QS-21. CoPoP liposomes give rise to rapid antigen particleization that is stable in biological media. In this collaborative Phase I SBIR proposal, we will assess the impact of lyophilization on the conformational and thermal stability of the resulting lyophilized vaccine, evaluated by biochemical and biophysical assays, and its efficacy will be assessed by functional immunogenicity in mice. This project will assess the feasibility of breaking the cold-chain requirements for a next-generation particle vaccine system, which could be critical for resource-limited settings. In collaboration with the Texas Biomedical Research Institute (TBRI), a transgenic mouse model for SARS-CoV- 2 infection will be used to study the thermostability on protection induced by the lyophilized, RBD particle vaccine. 1