In the studies, mice and ferrets vaccinated with Vical’s lead DNA vaccine candidate and those which received a blank DNA control were challenged with the H5N1 avian flu virus. All vaccinated animals survived while those which received the control did not survive.
In addition to providing complete protection against the virus, the company’s lead DNA vaccine candidate also prevented weight loss in all animals, suggesting that it is able to provide protection against serious flu-related sickness as well as death.
The company also said that a simplified version of the vaccine candidate using only two of the three components provided high levels of protection against multiple human flu strains, which is important because a pandemic could arise from a strain other than H5N1.
“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 Webby. “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.”