COVID-19 Vaccine Manufacturing Processes: Making the Molecules to Solve the Pandemic

Since the first report of the full genome sequence of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of the coronavirus disease 2019 (COVID-19) pandemic, many universities and pharmaceutical/biotechnology companies have worked to identify potential vaccine candidates to end this pandemic. With respect to the identity of the actual drug substance (DS), approved COVID-19 vaccines fall into one of four general categories: mRNA-, viral vector-, whole inactivated virus-, and protein-based vaccines. The manufacturing processes to deliver these vaccines vary broadly, with production from Escherichia coli to Sf9 insect cells, Chinese hamster ovary (CHO) cells, or enzymatic reactions, while purification for these products can be as simple as buffer exchange or require extensive recovery and chromatographic efforts. Here, we explain which processes are used for each vaccine category, discuss their individual challenges, and look at how the portfolio of vaccine candidates can come together to help solve the pandemic.