By Robert Preidt

　　Thursday, February 16, 2006

　　THURSDAY, Feb. 16 (HealthDay News) —— Researchers say they've developed a commercially viable process that could enable the mass production of flu vaccines within weeks, instead of the months it now takes.

　　This approach uses a purified protein from the surface of a virus called hemagglutinin (the "H" in a virus' designation —— for example —— the H5N1 bird flu virus) to trigger an immune response to a specific strain of virus.

　　The genes responsible for production of hemagglutinin are inserted into a pathogen called a baculovirus, which are then used to infect specific host cells. Those infected cells produce recombinant hemagglutinin (rHA).

　　Phase II clinical trials show that the vaccines produced using this method are safe and trigger an immune response equal to or greater than conventional chicken egg-based vaccines.

　　The researchers say they've successfully produced rHA from four strains of influenza that may trigger a pandemic —— H5, H7, H9 and H2 —— at levels where the cost of vaccine manufacturing would be equal to, or less than, that of traditional egg-based vaccines.

　　The results were reported Thursday at the American Society for Microbiology's Biodefense Research meeting, in Washington, D.C.

　　"The next flu pandemic could happen any time," said researcher Keyang Wang, of Protein Sciences Corp. "The most effective method to control such an outbreak is the widespread use of a vaccine, preferably in a proactive manner, so that the immune system is primed prior to actual virus exposure. The traditional egg-based method requires three to six months to develop the vaccine. With our cell-based method, as soon as the pandemic strain is identified, a matched vaccine can be massively produced within four weeks."