Development of a rapid response nucleic acid vaccine strategy for coronavirus epidemics

摘要 为应对新冠肺炎（SARS-CoV-2）大流行，本R44 AI 138733补充建议- 01将利用我们最先进的核酸疫苗战略，其中一些是根据这一战略开发的。 家长补助在此，我们要求补充资金，以开发候选COVID-19 DNA和RNA疫苗 表达针对SARS-CoV-2刺突蛋白的最佳设计的免疫原。核酸（DNA和RNA） 疫苗为新出现的传染病提供了快速反应解决方案， 因为只需要病原体的部分基因序列就可以产生新的疫苗。以下体内 递送，DNA和RNA疫苗导致抗原的原位产生，否定了对复合物的需要。 纯化重组蛋白（灭活或减毒活蛋白）所需的生产和工艺开发 疫苗。核酸也可以低成本制造，并且在室温下非常稳定 从而消除了对冷链的需求。这大大节省了推进新技术所需的时间。 从基因序列鉴定到临床试验，并将其分发给人口。此外，本发明还提供了一种方法， 可能是由于核酸疫苗在体内以其天然构象呈现抗原的能力， 与抗体诱导的免疫应答相比，抗体应答通常具有更高的亲合力和更宽的特异性。 通过亚单位蛋白疫苗。此外，抗原的细胞内表达也诱导强的T细胞应答 包括有效的CD 8 + T细胞反应，可以更广泛地识别不同的病毒株， 通过增强感染清除来保护。我们的方法将比较我们优化的DNA和RNA 疫苗平台技术单独和组合，以确定一种领先的方法， 并且在单次给药后中和抗体的保护水平的最快速发展。此外，本发明还提供了一种方法， 由于在我们实验室中测试的核酸疫苗已显示诱导抗体和/或T细胞应答， 在利用母基金进行的通用流感疫苗研究中，我们会 确定候选疫苗是否对其他冠状病毒株表现出交叉反应， 预防未来可能流行或大流行的冠状病毒株。我们的目标包括：目标1- SARS-CoV-2 DNA和RNA疫苗的设计和免疫原性比较目标2 -最大化 核酸疫苗免疫原性及DNA和复制子mRNA疫苗的快速制备 以及优化DNA和mRNA制剂。目标3 -安全和 在临床前非人灵长类动物模型中，领先的COVID-19核酸±蛋白疫苗的免疫原性。 如果成功，应确定用于I期人体临床试验的主要候选COVID-19核酸疫苗。

ABSTRACT In response to the emerging COVID-19 (SARS-CoV-2) pandemic, this supplement proposal to R44 AI138733- 01 will leverage our cutting-edge nucleic acid vaccine strategies, some of which that were developed under this parent grant. Here, we request supplement funding to develop candidate COVID-19 DNA and RNA vaccines expressing optimally designed immunogens for the SARS-CoV-2 spike protein. Nucleic acid (DNA and RNA) vaccines offer significant promise for providing a rapid response solution to emerging infectious diseases because only a partial genetic sequence of the pathogen is needed to generate a new vaccine. Following in vivo delivery, DNA and RNA vaccines lead to in situ production of antigens, negating the need for a complex manufacturing and process development required for purified recombinant protein, inactivated or live attenuated vaccines. Nucleic acids can also be manufactured at low cost and are very stable at room temperature eliminating the need for a cold chain. This provides a significant savings in the time needed to advance a new vaccine from identification of genetic sequence to clinical testing and distribute it to the population. In addition, possibly due to the ability of nucleic acid vaccines to present antigens in their natural conformation in vivo, antibody responses are generally of higher avidity and broader specificity when compared to antibody induced by subunit protein vaccines. Further, the intracellular expression of antigens also induces robust T cell responses including potent CD8+ T cell responses that can more broadly recognize different viral strains and mediate protection via enhanced clearance of the infection. Our approach will compare our optimized DNA and RNA vaccine platform technologies alone and in combinations to identify a lead approach that induces the highest and most rapid development of protective levels of neutralizing antibody after a single administration. In addition, since nucleic acid vaccines tested in our lab have been shown to induce antibody and/or T cell responses that induce cross-protective immunity in our universal influenza vaccine studies under our parent grant, we will determine if the candidate vaccines exhibit cross reactivity against other coronavirus strains for broader protection against future coronavirus strains with epidemic or pandemic potential. Our Aims include: Aim 1- Design and compare immunogenicity of candidate SARS-CoV-2 DNA and RNA vaccines. Aim 2 - Maximize immunogenicity of nucleic acid vaccines and rapid manufacture by combining DNA and replicon mRNA vaccines together or with recombinant protein and optimizing DNA and mRNA formulations. Aim 3 - Safety and immunogenicity of the lead COVID-19 nucleic acid ± protein vaccine in the preclinical nonhuman primate model. If successful, should identify a lead candidate COVID-19 nucleic acid vaccine for phase I human clinical trials.