Yang Zeyu, Paes Barbara Cristina Martins Fernandes, Fulber Julia Puppin Chaves, Tran Michelle Yen, Farnós Omar, Kamen Amine A
Viral Vectors and Vaccines Bioprocessing Group, Department of Bioengineering, McGill University, Montreal, QC H3A 0G4, Canada.
Vaccines (Basel). 2023 Apr 14;11(4):841. doi: 10.3390/vaccines11040841.
The administration of viral vectored vaccines remains one of the most effective ways to respond to the ongoing novel coronavirus disease 2019 (COVID-19) pandemic. However, pre-existing immunity to the viral vector hinders its potency, resulting in a limited choice of viral vectors. Moreover, the basic batch mode of manufacturing vectored vaccines does not allow one to cost-effectively meet the global demand for billions of doses per year. To date, the exposure of humans to VSV infection has been limited. Therefore, a recombinant vesicular stomatitis virus (rVSV), which expresses the spike protein of SARS-CoV-2, was selected as the vector. To determine the operating upstream process conditions for the most effective production of an rVSV-SARS-CoV-2 candidate vaccine, a set of critical process parameters was evaluated in an Ambr 250 modular system, whereas in the downstream process, a streamlined process that included DNase treatment, clarification, and a membrane-based anion exchange chromatography was developed. The design of the experiment was performed with the aim to obtain the optimal conditions for the chromatography step. Additionally, a continuous mode manufacturing process integrating upstream and downstream steps was evaluated. rVSV-SARS-CoV-2 was continuously harvested from the perfusion bioreactor and purified by membrane chromatography in three columns that were operated sequentially under a counter-current mode. Compared with the batch mode, the continuous mode of operation had a 2.55-fold increase in space-time yield and a reduction in the processing time by half. The integrated continuous manufacturing process provides a reference for the efficient production of other viral vectored vaccines.
病毒载体疫苗的接种仍然是应对当前2019年新型冠状病毒病(COVID-19)大流行的最有效方法之一。然而,对病毒载体的预先存在的免疫力会阻碍其效力,导致病毒载体的选择有限。此外,生产载体疫苗的基本批次模式无法经济高效地满足每年数十亿剂的全球需求。迄今为止,人类接触水泡性口炎病毒(VSV)感染的情况有限。因此,选择了一种表达严重急性呼吸综合征冠状病毒2(SARS-CoV-2)刺突蛋白的重组水泡性口炎病毒(rVSV)作为载体。为了确定最有效地生产rVSV-SARS-CoV-2候选疫苗的上游操作工艺条件,在Ambr 250模块化系统中评估了一组关键工艺参数,而在下游工艺中,开发了一种包括DNase处理、澄清和基于膜的阴离子交换色谱的简化工艺。实验设计旨在获得色谱步骤的最佳条件。此外,还评估了一种整合上游和下游步骤的连续模式生产工艺。rVSV-SARS-CoV-2从灌注生物反应器中连续收获,并通过膜色谱在三根依次以逆流模式运行的柱中进行纯化。与批次模式相比,连续操作模式的时空产率提高了2.55倍,处理时间减少了一半。这种整合的连续生产工艺为其他病毒载体疫苗的高效生产提供了参考。