Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/20/2009
Publication Date: 7/11/2009
Citation: Hai, R., Swayne, D.E., Palese, P. 2009. Live-attenuated influenza A virus vaccines using a B virus backbone [abstract]. Abstracts of the 28th Annual Meeting of the American Society for Virology, July 11-15, 2009, Vancouver, British Columbia, Canada. p. 159. Interpretive Summary:
Technical Abstract: The currently FDA-licensed live attenuated influenza virus vaccine contains a trivalent mixture of types A (H1N1 and H3N2) and B vaccine viruses. The two A virus vaccines have the backbone of a cold-adapted influenza A virus and the B virus vaccine has the six backbone segments derived from a cold-adapted influenza B virus. We propose a novel approach for the development of future live influenza virus vaccines through the use of a single backbone derived from the influenza B/Yamagata/88 virus with a truncation in the NS1 gene. A live-attenuated chimeric virus was generated by reverse genetics such that the virus possesses the gene encoding a modified H5 hemagglutinin (HA) from influenza A/Vietnam/1203/04 virus and the backbone from the influenza B/Yamagata/88 virus with a truncation in the NS1 gene. The chimeric virus requires trypsin for efficient growth in vitro and it is attenuated. It causes neither death when injected into the bloodstream of chickens nor infection when given through the birds' breathing passages. Initial animal studies indicate that vaccination with the chimeric virus protects mice against lethal challenge with an influenza A virus containing the Vietnam/1203/04 hemagglutinin. Our data suggests that novel and effective live-attenuated influenza (A and) virus vaccines can be generated from a single master strain, the influenza B/Yamagata/88 virus containing a truncation in the NS1 gene.