WARF: P06370US

High Titer Recombinant Influenza Viruses for Vaccines


Yoshihiro Kawaoka, Taisuke Horimoto, Shin Murakami

The Wisconsin Alumni Research Foundation (WARF) is seeking commerical partners interested in improved materials and methods for producing influenza virus.
OVERVIEWInfluenza is caused by the eight-segmented influenza virus. Vaccines can be used to prevent influenza, but traditional methods for producing influenza vaccine are slow and cumbersome.

To generate recombinant influenza vaccines, many researchers use an approach developed by the inventor, utilizing “reverse genetics” (see WARF reference number P99264US). In this method, plasmids containing the eight viral RNA segments, along with additional plasmids encoding proteins necessary for replication and transcription, are transfected into cell lines. Virus can then be harvested from these cells for vaccine production.

To improve yield of the H5N1 avian influenza strain and seasonal influenza viruses in cultured cells and in eggs, the typical medium used to replicate large quantities of infectious virus for vaccines, one can make what are called “6:2 reassortant viruses.” These viruses include the critical haemagglutinin (HA) and neuraminidase (NA) genes from strains circulating in the field and the six other viral RNA segments from a “harmless,” high-growing master strain.
THE INVENTIONUW-Madison researchers have developed an improved reassortant virus for use in producing high levels of the H5N1 avian influenza strain, as well as seasonal influenza strains. They discovered that using the NA segment from a “harmless” strain that grows well in eggs resulted in significantly greater amounts of infectious virus in eggs or cell lines. The inventors found that using a different isolate of this strain as a source for the other six viral segments also improves yield.
  • Production of influenza virus for viral mutagenesis studies, vaccine production and gene therapy
  • Provides improved methods for making vaccines against H5N1 and seasonal influenza
  • Results in a more than 10-fold increase in virus titer, or concentration
Contact Information
For current licensing status, please contact Jennifer Gottwald at or 608-960-9854.
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UW–Madison has the integrative capabilities to complete many key components of the drug development cycle, from discovery through clinical trials. As one of the top research universities in the world, and one of the two best-funded universities for research in the country, UW–Madison offers state-of-the-art facilities unmatched by most public universities.

These include the Small Molecule Screening Facility at the UW Comprehensive Cancer Center; the Zeeh Pharmaceutical Experiment Station, which provides consulting and laboratory services for developing formulations and studying solubility, stability and more; the Waisman Clinical Biomanufacturing Facility; the Wisconsin Institute for Medical Research, which provides UW–Madison with a complete translational research facility; and the innovative, interdisciplinary Wisconsin Institutes for Discovery, home to the private, nonprofit Morgridge Institute for Research and its public twin, WID, part of the university's graduate school. The highly qualified experts at these facilities are ready to work with you to create a library of candidates for drug development.