Bird-Flu Panacea: The Perfect Vaccine?

The University of Pittsburgh says its researchers have genetically engineered a vaccine that protects mice and chickens from the deadly bird-flu virus that's currently spreading across Asia.

Bird flu, specifically the H5N1 influenza virus, has killed more than 80 people in Asia, and human cases have spread as far west as Turkey.

The virus is based on living viral components, making it more potent than "dead" virus vaccines, the researchers said. The results of their efforts are in the Feb. 15 issue of the Journal of Virology.

"The results of this animal trial are very promising, not only because our vaccine completely protected animals that otherwise would have died, but also because we found that one form of the vaccine stimulates several lines of immunity against H5N1," said Dr. Andrea Gambotto, in a press release issued Thursday.

Gambotto, the lead author of the study, is an assistant professor in the departments of surgery and molecular genetics and biochemistry at the university's School of Medicine.

All of the mice immunized with a placebo (or inactive) vaccine experienced weight loss and died within six to nine days of avian-flu exposure. In contrast, most of the mice immunized with the H5N1 vaccine showed only mild and short-lived weight loss and survived, the press release stated.

Effectiveness for Humans Still Far From Clear

Whether this will translate into something useful for humans is yet to be seen.

Dr. David S. Fedson, a former adviser to several international vaccine advisory committees, said that even if the vaccine worked for humans, production would remain a limiting factor.

"These things are fast to do if you are in laboratory and you grow it in a petri dish -- but to commercialize is a different story. It takes years," he said. "Like so much interesting biology, it will be difficult to get this new technology established in the market place."