As evidenced by the COVID-19 pandemic, the rapid development and production of vaccines can be life-saving. Downstream processing continues to be the manufacturing bottleneck, but a switch from traditional batch chromatography-based platforms to continuous processing would allow higher productivity at lower cost. High throughput, high recovery, and simple unit operations are needed to realize this goal. Aqueous two-phase systems (ATPS) are an extraction strategy that combine product capture and purification by partitioning virus particles and contaminating host-cell proteins and DNA to different phases. These methods rely on biocompatible and environmentally-friendly components and do not require chemical regeneration. We have previously demonstrated recoveries from clarified cell supernatant of greater than 80% of porcine parvovirus (PPV) and human immunodeficiency virus-like particles (HIV VLP) in the polymer-rich phase of a PEG/sodium citrate ATPS, both in batch and continuous operational modes. However, to complete extraction of viral particles by ATPS, a continuous PEG removal step is required to prepare the product for final polishing and formulation. We have currently developed a back-extraction ATPS to remove the virus to a salt solution using a different system composition and pH. Then, using a series of two bench-top mixer-settlers, we have demonstrated continuous operation of both stages to purify PPV. This proof-of-concept study demonstrates that a two-stage aqueous two-phase system could be incorporated into a fully-continuous purification process that will make vaccine manufacturing faster, less expensive, and more reliable.

Continuous vaccine manufacturing using a two-stage aqueous two-phase system

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.