Phenotypic and genetic characterization of a next generation live-attenuated yellow fever vaccine candidate.

We assessed the genetic and phenotypic characteristics of a yellow fever vaccine candidate, which was cloned from a YF-VAX substrain selected for growth in Vero cells (vYF-247), during the manufacturing process from the master seed lot (MSL) and working seed lot (WSL) through to the drug substance (DS) stage. There were nine minor nucleotide variants observed from the MSL to the DS stage, of which five led to amino acid changes. The variant positions were, however, not known risks for any virulence modification.

Robust real-time cell analysis method for determining viral infectious titers during development of a viral vaccine production process.

The classical cell-culture methods, such as cell culture infectious dose 50% (CCID) assays, are time-consuming, end-point assays currently used during the development of a viral vaccine production process to measure viral infectious titers. However, they are not suitable for handling the large number of tests required for high-throughput and large-scale screening analyses. Impedance-based bio-sensing techniques used in real-time cell analysis (RTCA) to assess cell layer biological status in vitro, provide real-time data.