分类: 生物学 >> 病毒学 提交时间: 2020-02-25
摘要: Frequent outbreaks of coronavirus make the development of an effective vaccine imperative. Recently, vaccines based on in-vitro transcribed messenger RNA (mRNA) have shown great potential. The streamlined manufacturing of mRNA molecules, combined with the superior flexibility in the antigen screening, greatly accelerates the development process. When using an mRNA platform to develop a vaccine, initial antigen choice plays a crucial role in determining the final efficacy and safety of the vaccine. Furthermore, mRNA sequences that encode antigens require extensive optimization to ensure highly efficient and sustained expression. Our ongoing efforts to develop an effective mRNA vaccine against 2019-nCoV place emphasis on the virus-like particles (VLPs) as the presenting antigen. At the same time, our second fast track uses mRNA to express the receptor-binding domain of the spike protein(S-RBD). After extensive optimization, an mRNA cocktail containing three genes is able to produce 2019-nCoV virus-like particles highly similar to the native 2019-nCoV. Meanwhile, an mRNA vaccine candidate expressing S-RBD is being tested in mice for its immunogenicity. We will next compare both the efficacy and the safety of the two mRNA vaccines based on S-RBD and VLPs, respectively.
分类: 物理学 >> 交叉学科物理及相关领域的科学与技术 分类: 生物学 >> 病毒学 提交时间: 2020-02-25
摘要: 由于春运出湖北省高峰和全国各地管控开始之间的时间差,使得在这个时间段内,除湖北外的国内地区是个输入一代到感染二代之间独立自然连续传播体系。基于此,我们使用正态分布的线性叠加来拟合全国除湖北外每日新增的数据,简单模型预测和实际新增结果的高度吻合验证了除湖北外是个近似理想系统。拟合计算得到的新冠病毒可再生系数R0=2.2,一代到二代的峰值传播时间是7天。我们还讨论了偏离理想传播体系的原因并分析了一些省的特殊情况。