Flavivirus production in animal cell culture

Motivation

The 17D vaccine is often considered a “legacy” vaccine, i.e., the vaccine was developed in the 1930s before modern techniques were introduced for developing a vaccine. This does cause some complications in the 21st century. Current yellow fever vaccine manufacturing processes rely on embryonated chicken eggs, a slow and elaborate method which cannot be simply ramped up as vaccine demands promptly increase, leading to occasional shortages. Furthermore, adherent Vero cells were seen as a possible cell culture-based substrate. Previously, we have shown clear process improvement, by using suspension cells, such as BHK21 or EB66.

Our collaboration partner KU Leuven developed a novel vaccine platform technology, using the YF17D as a live viral vector to engineer novel vaccines against unmet medical needs. This plug-and-play technology has been validated using a series of target and model antigens, such as rabies, Zika, Ebola and Lassa.

*Figure 1: Classical production of YF17D in embryonated eggs (left) and next-generation vaccine process development (right).*

*Figure 1: Classical production of YF17D in embryonated eggs (left) and next-generation vaccine process development (right).*

Aim

Based on our previous knowledge for YFV production in suspension cells, we want to develop a novel straightforward manufacturing approach (readied for industrial scale) for these YF17D-based vaccines which is reliable and outcompetes the benchmark set by prior technology. Our approach should ideally be transferable to a wide range of different YF17D-based constructs, i.e. by process intensification and control for operation of high-cell-density perfusion cultivations with optimal infection conditions.

References

Nikolay, A.; Léon, A.; Schwamborn, K.; Genzel, Y.; Reichl, U.: Process intensification of EB66 ^® cell cultivations leads to high-yield yellow fever and Zika virus production. Applied Microbiology and Biotechnology 102 (20), pp. 8725 - 8737 (2018)

MPG.PuRe

DOI

publisher-version

Nikolay, A.; Casthilho, L. R.; Reichl, U.; Genzel, Y.: Propagation of Brazilian Zika virus strains in static and suspension cultures using Vero and BHK cells. Vaccine 36 (22), pp. 3140 - 3145 (2018)

MPG.PuRe

DOI

publisher-version

Kum, D.B., Mishra, N., Boudewijns, R. et al. A yellow fever–Zika chimeric virus vaccine candidate protects against Zika infection and congenital malformations in mice. npj Vaccines 3, 56 (2018).

Sanchez-Felipe, L., Vercruysse, T., Sharma, S. et al. A single-dose live-attenuated YF17D-vectored SARS-CoV-2 vaccine candidate. Nature 590, 320–325 (2021).