New Vaccine Protects Against Avian Flu

A bird flu vaccine under development protects mice and ferrets against the H5N1 strain of avian influenza and may also offer potential as a universal flu vaccine.

The vaccine, being developed by Vical Incorporated (San Diego, CA, USA), is targeted at three sections of DNA common to all viruses: the variable hemagglutinin surface protein (H5), the conserved nucleoprotein (NP), and the matrix protein (M2).

In studies conducted at St. Jude Children's Research Hospital (Memphis, TN, USA), 16 mice or six ferrets were vaccinated with this vaccine and then exposed to the highly virulent H5N1 avian influenza strain. All survived. Fourteen of 16 mice vaccinated with a simplified version of the vaccine, which only included NP and M2, survived with moderate weight loss. This suggests, but does not prove, that the vaccine provides cross-protection against several flu strains. Based on the results, the company is continuing to advance toward human testing of the DNA vaccine candidate.

"We are encouraged by the protection afforded by our avian flu vaccine and by the cross-protection data. Achieving cross-protection is the ultimate goal in flu vaccines, and the current studies provide evidence that such a goal may be feasible using a DNA vaccine targeting conserved influenza virus proteins and formulated with our proprietary Vaxfectin adjuvant,” said Vijay B. Samant, president and CEO of Vical.

"A vaccine that provides cross-protection against more than one strain of flu is important for addressing a pandemic flu threat because it is likely that the H5N1 virus could mutate before it becomes transmissible from human to human,” said Dr. Richard Webby, Ph.D., of St. Jude's, who tested the vaccine. "The current data show that this vaccine has the potential to achieve cross-protection because it targets two conserved flu virus proteins as well as H5.”



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St. Jude Children's Research Hospital