Facultad de Microbiología, Instituto Clodomiro Picado, Universidad de Costa Rica, San José, Costa Rica.
Virology-CIET (Research Center for Tropical Diseases), Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
Sci Rep. 2021 May 10;11(1):9825. doi: 10.1038/s41598-021-89242-z.
In the current global emergency due to SARS-CoV-2 outbreak, passive immunotherapy emerges as a promising treatment for COVID-19. Among animal-derived products, equine formulations are still the cornerstone therapy for treating envenomations due to animal bites and stings. Therefore, drawing upon decades of experience in manufacturing snake antivenom, we developed and preclinically evaluated two anti-SARS-CoV-2 polyclonal equine formulations as potential alternative therapy for COVID-19. We immunized two groups of horses with either S1 (anti-S1) or a mixture of S1, N, and SEM mosaic (anti-Mix) viral recombinant proteins. Horses reached a maximum anti-viral antibody level at 7 weeks following priming, and showed no major adverse acute or chronic clinical alterations. Two whole-IgG formulations were prepared via hyperimmune plasma precipitation with caprylic acid and then formulated for parenteral use. Both preparations had similar physicochemical and microbiological quality and showed ELISA immunoreactivity towards S1 protein and the receptor binding domain (RBD). The anti-Mix formulation also presented immunoreactivity against N protein. Due to high anti-S1 and anti-RBD antibody content, final products exhibited high in vitro neutralizing capacity of SARS-CoV-2 infection, 80 times higher than a pool of human convalescent plasma. Pre-clinical quality profiles were similar among both products, but clinical efficacy and safety must be tested in clinical trials. The technological strategy we describe here can be adapted by other producers, particularly in low- and middle-income countries.
在当前由 SARS-CoV-2 爆发引起的全球紧急情况下，被动免疫疗法作为 COVID-19 的一种有前途的治疗方法出现了。在动物源性产品中，马制剂仍然是治疗动物咬伤和蜇伤的基石疗法。因此，我们借鉴了几十年生产蛇抗毒液的经验，开发并临床前评估了两种针对 SARS-CoV-2 的多克隆马制剂，作为 COVID-19 的潜在替代治疗方法。我们用 S1（抗 S1）或 S1、N 和 SEM 镶嵌（抗混合）病毒重组蛋白混合物免疫两组马。在初次免疫后 7 周，马达到了最大抗病毒抗体水平，并且没有出现主要的急性或慢性临床不良反应。通过辛酸对超免疫血浆进行沉淀制备了两种全 IgG 制剂，然后配制用于肠胃外使用。两种制剂都具有相似的理化和微生物质量，并且对 S1 蛋白和受体结合域（RBD）具有 ELISA 免疫反应性。抗混合制剂也对 N 蛋白表现出免疫反应性。由于高抗 S1 和抗 RBD 抗体含量，最终产品表现出对 SARS-CoV-2 感染的高体外中和能力，比人类恢复期血浆池高 80 倍。两种产品的临床前质量特征相似，但临床疗效和安全性必须在临床试验中进行测试。我们在这里描述的技术策略可以被其他生产商采用，特别是在中低收入国家。
