June 6-11, 2010
The traditional influenza vaccine, trivalent inactivated virus (TIV) has been in use in the United States in one form or another since the 1940s. The system for production involves injecting influenza virus into embryonated hen’s eggs, harvesting the allantoic fluid containing the virus, inactivation with formalin, disruption of the virus with non-ionic detergent, zonal centrifugation to enrich for antigen and a second inactivation step. The recent appearance of the H1N1 swine virus has provided an opportunity to test the pandemic response system established over the past ten years. What we find is that the public health system seems to work well, but supply of pandemic vaccine has fallen short of original estimates. The shortfall can be linked directly to the poor growth of the H1N1 production strain in eggs. Our laboratory has developed a method for producing the globular head of influenza hemagglutinin, fused genetically to flagellin, the ligand for Toll-Like Receptor 5. The chimeric fusion protein, produced in E. coli using standard rDNA methods, has been shown to be highly immunogenic in humans with an optimal dose of 2 ug. This changes the production scheme from a complex and poorly scalable egg-by-egg process to a simple fermentation and purification process. A single 1000L fermentation will yield 200 million monovalent doses of vaccine. The fermentation cycle is 6 days, and the purification cycle is 6 days. The fermentation and purification processes utilize commonly available equipment, providing the option of making this type of vaccine in multiple locales for reasons of local autonomy. We learned of the H1N1 outbreak in Mexico on April 24th 2009. In three weeks we were able to create a new E. coli seed strain and produce pure protein for testing in animals. This rapid response to a new influenza virus coupled with a highly scalable and transferable manufacturing process presents a powerful tool for combating a pandemic.
Thomas Hofstaetter, "POTENT, RAPID AND COST-EFFECTIVE INFLUENZA VACCINES MADE IN E. COLI" in "Vaccine Technology III", John G. Auniņš,Merck, USA; Barry C. Buckland, BiologicB, USA; Kathrin U. Jansen, Pfizer, USA; Paula Marques Alves, IBET, Portugal Eds, ECI Symposium Series, (2010). http://dc.engconfintl.org/vaccine_iii/2