Serum for Vaccine Cell Culture – Trick or Treat?
Using fetal bovine serum in vaccine cell culture production is commonplace. The cells used to produce viruses, such as VERO and MDCK, are more sensitive to changes in cell culture media than other cell lines used in biomanufacturing. The goal of cell based vaccine production is to produce as much viral yield as possible and fetal bovine serum helps manufacturers reach this goal. Serum is often used to promote both cell growth and viral productivity and it is often easier to use fetal bovine serum than to optimize a serum-free media. In fact, cell viability, growth and productivity can be significantly reduced when serum is removed.
The problem is that this treat doesn’t come without a trick. Using animal derived ingredients like fetal bovine serum in cell culture is undesirable because these components are undefined and have high batch-to-batch variation that leads to unpredictable results. The Food and Drug Administration (FDA) and other regulatory bodies discourage use of these animal components due to serious safety concerns involving the risk of viral and prion (the infectious causative agent associated with Mad Cow Disease) contamination. With these risks and concerns come extensive regulatory and sourcing issues to meet the FDA’s safety requirements. In addition, it has been reported that more fetal bovine serum is sold than is made and this is likely to lead to variation.
So is serum a trick or treat, maybe it is a little of both? The good news is that there are innovative new cell culture solutions. Recombinant proteins including albumin and transferrin have been proven to keep viral yield up while alleviating the concerns of animal derived materials. In addition, recombinant proteins reduce logistical challenges, risk mitigation steps, and regulatory documentation. Both recombinant proteins are available from InVitria. In addition, companies like Sigma-Aldrich, PeproTech and Ajinomoto offer recombinant forms of common growth factors including EGF, IGF (LongR3) and FGF. The use of recombinant proteins and other animal-component free growth supplements needs to be examined – so we can get the treat without the trick!
Please comment. I would like to hear your thoughts on whether you think serum in vaccine manufacturing is a trick or treat. Also what are new innovative solutions to keep viral yield up without using animal components?