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

摘要 为应对新出现的新冠肺炎(SARS-CoV-2)大流行，本补充建议对R44 AI138733- 01将利用我们的尖端核酸疫苗策略，其中一些策略是在 家长助学金。在这里，我们请求补充资金来开发候选的新冠肺炎DNA和RNA疫苗 表达针对SARS-CoV-2刺突蛋白的优化设计的免疫原。核酸(DNA和RNA) 疫苗为应对新出现的传染病提供了一种快速反应的解决方案 因为只需要病原体的部分基因序列就可以产生新的疫苗。在体内追踪 递送，DNA和RNA疫苗导致原位产生抗原，而不需要复杂的 灭活或减毒纯化重组蛋白所需的制造和工艺开发 疫苗。核酸也可以低成本制造，并且在室温下非常稳定。 消除了冷链的需要。这大大节省了推进新的 疫苗从基因序列识别到临床测试，并将其分发给人群。此外, 可能是由于核酸疫苗在体内以自然构象呈现抗原的能力， 与抗体诱导相比，抗体反应一般具有更高的亲和力和更广泛的特异性 通过亚单位蛋白疫苗。此外，抗原在细胞内的表达也能诱导强大的T细胞反应 包括强大的CD8+T细胞反应，可以更广泛地识别不同的病毒株并介导 通过加强对感染的清除来保护。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，以确定领先的方法，诱导最高 单次给药后，中和抗体保护性水平发展最快。此外, 由于我们实验室测试的核酸疫苗已被证明能诱导抗体和/或T细胞反应， 在我们的通用流感疫苗研究中引入交叉保护免疫，我们将 确定候选疫苗是否表现出与其他冠状病毒株的交叉反应 对未来可能流行或大流行的冠状病毒株的保护。我们的目标包括：目标1- 设计并比较候选SARS-CoV-2 DNA和RNA疫苗的免疫原性。目标2-最大化 核酸疫苗的免疫原性及DNA和复制子联合疫苗的快速制备 与重组蛋白一起或与重组蛋白一起使用，并优化DNA和mRNA配方。目标3--安全和 新冠肺炎核酸±蛋白疫苗在临床前非人灵长类动物模型中的免疫原性 如果成功，应该会确定一种主要的候选新冠肺炎核酸疫苗，用于I期人类临床试验。

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.