Smart Scale-Up: Expanding Viral Vectors With Microcarrier Bead Technology

By Heidi Trusheim, Director, Process Development, and Edward Fix, Director, Manufacturing, IDT Biologika

As health professionals administer the Pfizer-BioNTech and Moderna mRNA-based COVID-19 vaccines, other companies are working to develop viral vector-based vaccines to combat coronavirus and other viral diseases. Viral vectors require cells to grow, but certain viral vectors can only be produced on adherent cell cultures, while others can also be produced on suspension cell cultures. Vaccine manufacturers often encounter significant challenges in scaling up the adherent cell cultures used for these treatments, and novel technologies are needed to facilitate safe, rapid production.

Microcarrier bead technology is a relatively new, but proven, technology for imprinting adherent cells onto carriers, which can then be grown in SUT reactors and scaled up for clinical and commercial production volumes. When combined with complimentary cell lines, such as Vero, microcarrier beads can help companies make better use of the equipment and systems they already have in place for suspension cell technology.

Some companies may lack the analytical capabilities to characterize cell lines that will replicate target viruses well enough to yield titers sufficient for high-volume production or lack the possession of qualified cells. Relying on a CDMO can help to accelerate early-phase development and reduce costs, but companies must ensure their partner has the process understanding necessary to apply this technology and these cell types specifically to their project.