COVID-19 has become one of the biggest health concern, along with huge economic burden. With no clear remedies to treat the disease, doctors are repurposing drugs like chloroquine and remdesivir to treat COVID-19 patients. In parallel, research institutes in collaboration with biotech companies have identified strategies to use viral proteins as vaccine candidates for COVID-19. Although this looks promising, they still need to pass the test of challenge studies in animal models. As various models for SARS-CoV-2 are under testing phase, biotech companies have bypassed animal studies and moved to Phase I clinical trials. In view of the present outbreak, this looks a justified approach, but the problem is that in the absence of animal studies, we can never predict the outcomes in humans. Since animal models are critical for vaccine development and SARS-CoV-2 has different transmission dynamics, in this review we compare different animal models of SARS-CoV-2 with humans for their pathogenic, immune response and transmission dynamics that make them ideal models for vaccine testing for COVID-19. Another issue of using animal model is the ethics of using animals for research; thus, we also discuss the pros and cons of using animals for vaccine development studies.

中文翻译：

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当前针对 COVID-19 的全球疫苗和药物努力：绕过动物试验的利弊

随着巨大的经济负担，COVID-19 已成为最大的健康问题之一。由于没有明确的治疗方法，医生们正在重新利用氯喹和瑞德西韦等药物来治疗 COVID-19 患者。与此同时，研究机构与生物技术公司合作，确定了使用病毒蛋白作为 COVID-19 候选疫苗的策略。尽管这看起来很有希望，但它们仍然需要通过动物模型的挑战研究测试。由于 SARS-CoV-2 的各种模型正处于测试阶段，生物技术公司已绕过动物研究，转向 I 期临床试验。鉴于目前的爆发，这看起来是一个合理的方法，但问题是，在没有动物研究的情况下，我们永远无法预测人类的结果。由于动物模型对疫苗开发至关重要，而 SARS-CoV-2 具有不同的传播动力学，在本综述中，我们将 SARS-CoV-2 的不同动物模型与人类的致病、免疫反应和传播动力学进行了比较，使其成为理想的模型COVID-19 的疫苗测试。使用动物模型的另一个问题是使用动物进行研究的伦理问题；因此，我们还讨论了使用动物进行疫苗开发研究的利弊。