(8a) Pre-Clinical Manufacturing and Process Intensification of a Subunit Vaccine for COVID-19 (Faculty Candidate)

Rapid manufacturing and distribution of vaccines at global scale is a key tenant of response to the COVID-19 pandemic, which spread globally on the order of weeks. Elimination of the disease will require several billion doses of a vaccine, based on the basic reproductive number of at least 2-3 estimated by current models. A majority of these doses need to be deployed in low- and middle-income countries, which are especially vulnerable to the disease, and could serve as epicenters for resurgence. Subunit vaccines are enticing candidates because they are potentially compatible with existing platforms for the manufacturing of similarly sized proteins at global scale, like the production of billions of yearly doses of Hepatitis B vaccine and insulin in the yeast Komagataella phaffii (Pichia pastoris). The first six vaccines for COVID-19 to enter human trials, however, did not include a subunit vaccine. What is needed are platforms for the rapid generation of subunit vaccine candidates for pre-clinical testing that are subsequently amenable to scaled up manufacturing.

We expressed the SARS-CoV-2 receptor binding domain (RBD) in K. phaffii. Speed of the yeast host, combined with InSCyT, our benchtop scale, continuous, end-to-end manufacturing platform, enabled purification and characterization of RBD in quantities and qualities sufficient for pre-clinical studies in less than one month. During pre-clinical studies, we used modern diagnostic tools like RNAseq and rapid genome engineering tools like CRISPR to improve specific and volumetric productivity of our host and process by >5x. Our intensified process demonstrates rapid development of a manufacturing process compatible with existing centralized and distributed manufacturing platforms, and within the low cost necessary for global distribution.