开发 COVID-19 疫苗是全球优先事项。 在这篇文章中，作者对疫苗的研发和发展现状进行了回顾和评价。
Covid-19 由 SARS-CoV-2 病毒引起的疾病在过去几个月中在世界范围内稳步增加，而且看不到尽头。 到目前为止，还没有 疫苗 批准治愈这种衰弱 疾病 这已在全球感染了约 2 万人，并导致其中约 120,000 人死亡 (1)，这一数字为 6%。 这 6% 的死亡率是全球平均水平，欧盟的死亡率约为 10%，而世界其他地区的死亡率约为 3%。 也有大约 450,000 人康复，这个数字约为 23%。
制药和生物技术公司以及世界各地的大学和研究机构正在以极大的热情开发 av疫苗 against COVID-19 that could become the saviour of people and prevent them for getting the disease. This article will focus on the concept of vaccine development for viruses, the types (category) of 疫苗 being developed for COVID-19 by numerous companies, institutes and consortiums around the world who are engaged in its research and development and its present status with emphasis on vaccine candidates that have already entered clinical trials.(1).
病毒疫苗开发涉及制备病毒分子的生物制剂，该病毒分子由减毒活病毒、灭活病毒、空病毒颗粒或病毒肽和蛋白质单独或组合组成，一旦注射到健康个体中，就会触发其免疫系统产生针对病毒分子的抗体，从而在实际感染发生时保护个体。 这些充当抗原的病毒分子和蛋白质可以在外部（在实验室中）产生或在个体（宿主）内部产生（表达）以产生免疫反应。 过去十年左右生物技术领域的技术进步也在疫苗开发中发挥了重要作用，产生了在宿主体内或体外产生病毒抗原的新方法，这些方法有助于疫苗的安全性，大规模制造的稳定性和易用性。
的类型 疫苗 under development for COVID-19 fall into three broad different categories based on the nature of technology platforms to generate viral antigens (2). The first category comprises of using the live attenuated vaccine (that involves weakening the virulence of SARS-CoV-2 virus) or inactivated virus (in which the inactivation is performed using chemical means) and injecting it in the host to develop an immune response. This category represent the way in which 疫苗 were made conventionally. The second category in vogue focuses on the production (expression) of viral proteins inside the host (humans) by use of nucleic acids (plasmid DNA and mRNA) and viral vectors (replicating and non-replicating) containing viral genes. These nucleic acids and viral vectors use cellular machinery for the expression of viral proteins within the host upon injection, thereby triggering an immune response. The third category involves development of empty (without genome) viral like particles (VLPs) expressing viral proteins on their surface, use of synthetic peptides (selected parts of viral proteins) and recombinant production of viral proteins as antigens in various expression systems at a large scale outside the human host, and then using them as vaccine candidates alone, or in combination.
As of April 10th 2020, a total of 69 companies, research institutes, universities and/or a consortium of the above (3, 4) are actively engaged at an unparalleled speed in a race against time for the development of COVID-19 vaccine. These companies can be divided into either of the three categories mentioned above based on the technology they are using for COVID-19 vaccine development. Seven of these companies are exploiting the way 疫苗 are manufactured by the first category and the remaining 62 companies are almost equally divided (30 in the second category which uses plasmid DNA, RNA and replicating and non-replicating viral vectors while 32 in the third category which uses VLPs, peptides and recombinant viral proteins) in terms of the technologies used for vaccine manufacturing for COVID-19. Most of these companies are in exploratory or pre-clinical stages of research and development. However, six of these companies have advanced their candidate 疫苗 into clinical trials which are listed in Table I (information sourced from references 2-6). All these 疫苗 fall into the second category.
基于所使用的技术平台的 COVID-19 疫苗开发分别属于第一类和 10% 的第二类和 43.5% 的第三类（图 46.5）。 根据地理位置，北美（美国和加拿大）引领 COVID-1 疫苗开发，公司比例最高（19%），其次是欧洲（40.5%）、亚洲和澳大利亚（27.5%）以及中国（19%）。 参见图 13。
图 1. COVID-19 疫苗开发的类别
Table I. COVID-19 疫苗 在临床试验中
图 2. 从事 COVID-19 疫苗研发的公司的地理分布。
The majority use of categories 2 and 3 in vaccine development for COVID-19 suggests the exploitation of modern state of the art technologies that have led to the ease of manufacturing and might contribute to the safety, stability and effectiveness of vaccine preparations. It is sincerely hoped that the current 疫苗 in clinical trials and the ones that follow would result in an effective vaccine candidate that can be fast tracked for approval by the regulatory authorities for vaccinating the human population, thereby preventing them from contracting the COVID-19 disease, and overcoming the misery that has been caused by this debilitating disease.
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参考文献：
1. Worldometer 2020。COVID-19 冠状病毒大流行。 最后更新时间：14 年 2020 月 08 日，格林威治标准时间 02:XNUMX。 可在线获取 https://www.worldometers.info/coronavirus/ 13 年 2020 月 XNUMX 日访问。
2. Thanh Le T.、Andreadakis, Z. 等人，2020 年。COVID-19 疫苗开发前景。 09 年 2020 月 XNUMX 日发布。 Nature Reviews Drug Discovery DOI： http://doi.org/10.1038/d41573-020-00073-5
3. 米尔肯研究所，2020 年。COVID-19 治疗和疫苗追踪器。 可在线获取 https://milkeninstitute.org/sites/default/files/2020-03/Covid19%20Tracker_WEB.pdf 13 年 2020 月 XNUMX 日访问。
4. WHO, 2020. DRAFT landscape of COVID-19 candidate 疫苗 – 20 March 2020. Available online at https://www.who.int/blueprint/priority-diseases/key-action/novel-coronavirus-landscape-ncov.pdf?ua=1 13 年 2020 月 XNUMX 日访问。
5. 监管重点，2020 年。COVID-19 疫苗追踪器。 可在线获取 https://www.raps.org/news-and-articles/news-articles/2020/3/covid-19-vaccine-tracker 13 年 2020 月 XNUMX 日访问。
6. USNLM 2020. COVID-19 临床试验可在线获取： https://www.clinicaltrials.gov/ct2/results?cond=COVID-19 13 年 2020 月 XNUMX 日访问。
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