Vaccine Manufacturing Processes
A move away from serum-based cell culture media is occurring in the protein therapeutics arena, as evidenced by the fact that no new serum-based processes will be accepted by the industry, according to Hikmat Bushnaq-Josting, technical manager for SAFC in Europe.
“If there is a serum-free alternative it will be favored, and new cell lines are being developed that will grow in serum-free media. The older lines are suspect in that they may carry retroviruses or tumorogenic factors, while at the same time there is a trend toward the use of cells that will grow in suspension.”
Today, suspension culture is recognized for the number of virtues that it displays when compared to two-dimensional, adherent culture systems. Trypsinization is not required for harvest, the systems are more homogeneous, it is easier to sample and transfer, and it is much easier to develop processes for suspension cultures and scale them up.
The downside, however, is that the behavior of cells grown adherently is more natural and the reaction kinetics between virus and host cell are faster and more efficient. Still, the benefits are tending to move the industry in the direction of suspension cultures.
The classic cell lines, such as MDCK, Vero, and HeLa, were not developed for bioproduction, so Bushnaq-Josting’s recommendations are that labs should ease into adoption of this changing picture.
“It is also important to develop flexible facilities that can be adapted to different vaccines reflecting the particular pandemic for which the vaccines are being developed,” Bushnaq-Josting added. This consideration sets vaccine technology somewhat apart from other protein-based therapeutics, in that the logistic requirements of the latter are somewhat more predictable.
In discussing strategies to minimize cost and maximize flexibility, Bushnaq-Josting suggested that manufacturers of therapeutic proteins should outsource media and buffer manufacturing during the clinical phases of a program until a monthly consumption of ca. 10,000 L is reached.
Also noted is a move toward more and more outsourcing of the liquid products preparation, while at the same time trending away from total customization to a more standard packaging format. These approaches will drive stronger partnerships between liquid manufacturers and vaccine manufacturers to be prepared for pandemic situations and overcome a potential capacity crunch.
“The critical question is: what is more flexibility and ease of scaleup worth? What are the losses if you don’t have enough process liquids when the market demands your products?”
Sartorius Stedim Biotech has made major inroads into the disposable products sector in recent years. This decision has had a positive effect on the company’s bottom line, given that the world-wide economic downturn has held back many firms both in and out of the biotechnology area from making major investments in capital equipment.
Michelle Dean, field marketing manager for Sartorius Stedim Biotech in the U.K. discussed the company’s range of products designed for both wet and dry solutions. “Our range of standard scalable Flexel® 3-D bags are specifically designed for process-development applications and small-volume biomanufacturing.”
According to Dean, these products are composed of four layers of different materials to provide a secure holding technology. This includes a straightforward scaleup operation from 5 L up to 3,000 L using the same S40 film and 3-D bag technology.
At all volumes these features endow the products with high robustness and reliability, and the 3,000 L volume moves the disposables into the range previously occupied solely by reusable processing equipment.
The disposable technology can now provide rapid deployment of complete single-use engineered liquid handling and storage through a range of accessories, a validation package, and a global security strategy, she said.