Vaxarray potency assay for rapid assessment of “pandemic” flu vaccines
June 17-22, 2018
A first-in-class “on-demand” potency assay was developed for flu vaccines produced in response to the most concerning emergent influenza A subtypes. Specifically, the World Health Organization has recommended the development of new candidate vaccine viruses for deadly avian influenza H5 and H7 subtypes. The VaxArray Influenza Pandemic HA (VXI-pHA) potency assay was designed to probe multiple subtype-specific conserved epitopes on the hemagglutinin protein for H5, H7, and H9 subtypes. The goal was to optimize the probability that the ready-to-use assay would work for a new H5, H7, or H9 flu vaccine in order to streamline potency determination, potentially reducing the time to deliver life-saving vaccine by weeks or possibly even months. The performance of this new potency test was evaluated using a large set of influenza viruses and vaccines spanning 16 years of antigenic drift, including the most recent pre-pandemic vaccine being developed against the deadly “5th wave” A/H7N9 virus. Against a panel of 46 potentially pandemic influenza strains, the VXI-pHA assay demonstrated coverage of 93%, 91%, and 100% for H5, H7, and H9 antigens, respectively. The assay demonstrated high sensitivity with linear dynamic ranges more than 150-fold and quantification limits ranging from 1-5 ng/mL. For three production lots of H7N9 monobulk drug substance, the assay exhibited excellent accuracy (100 ± 6%) and analytical precision (CV 6 ± 2%). The high assay sensitivity enabled robust detection and quantification of hemagglutinin in crude in-process samples and low dose adjuvanted vaccines with an accuracy of 100 ± 10%.
Kathy Rowlen, "Vaxarray potency assay for rapid assessment of “pandemic” flu vaccines" in "Vaccine Technology VII", Amine Kamen, McGill University Tarit Mukhopadhyay, University College London Nathalie Garcon, Bioaster Charles Lutsch, Sanofi Pasteur Eds, ECI Symposium Series, (2018). https://dc.engconfintl.org/vt_vii/38