Feb. 22 (Bloomberg) -- An experimental treatment made from human proteins neutralized a wide variety of influenza germs in a study, including the H5N1 avian flu, the 1918 pandemic virus and some seasonal forms of the illness.

Mice that were injected with the treatment three days after being infected with bird flu didn’t show any symptoms, according to an Online report in the journal Nature Structural and Molecular Biology. The treatment also protected mice from other strains of flu virus, researchers said.

Normally, flu vaccines are specific to only one strain of virus at a time. The new results suggest a single treatment may be developed that works for many strains. Such a treatment could be used to help slow outbreaks while more precise treatments are developed, researchers said. Human trials for proteins could begin as soon as the 2011-2012 winter flu season, they said.

“These antibodies have important therapeutic potential and pave the way for the generation of a universal vaccine,” said Ruben Donis, a study author and researcher at the Centers for Disease Control and Prevention, in a conference call.

The treatment is made from a laboratory-produced version of human immune system defenses called monoclonal antibodies. It targets a different part of the flu virus than the body’s naturally produced antibodies.

The body produces antibodies to the rounded head of the flu virus, which can mutate quickly, said Wayne Marasco, an associate professor of medicine at Harvard Medical School in Boston and one of the study’s authors. The neck of the virus remains relatively stable, so that’s what he and his team targeted, he said.

‘Feeling Confident’

“We are all feeling confident that we have opened another avenue of research,” Marasco said.

The study was done by researchers at Dana-Farber Cancer Institute and Harvard Medical School in Boston; the Burnham Institute for Medical Research in La Jolla, California, and the CDC’s influenza division. The National Institutes of Health funded the work.

“This is an elegant research finding that holds considerable promise for further development into a medical tool to treat and prevent seasonal as well as pandemic influenza,” said Anthony Fauci, the director of by the National Institute of Allergy and Infectious Diseases, in a statement.

The treatment isn’t universal and doesn’t cover all viruses, said William Schaffner, an infectious-disease specialist at Vanderbilt University in Nashville, Tennessee. Testing is still in an early phase, and human medical trials will have to be done to see if it’s safe. The findings are still encouraging, Schaffner said.

‘Two Roads at Once’

“This could allow us to go down two roads at once: a vaccine for better protection, and therapeutic antibodies that would be potentially useful in treatment,” Schaffner said. He wasn’t involved in the research.

Though the treatment would require an intravenous infusion and would be more expensive than a pill, having such a drug would help the effort to control infections, Schaffner said. Tamiflu, the Roche Holding AG pill for influenza, can’t fight most infections that have been diagnosed in the U.S. flu season so far, according to the CDC.

The researchers haven’t partnered with a pharmaceutical company to develop a product yet, Marasco said.

“This is the first announcement of the work, so we’ve been fairly tightlipped as far as letting pharma know,” Marasco said. “We’re interested in doing that now.”

To contact the reporter on this story: Elizabeth Lopatto in New York at elopatto@bloomberg.net.

Last Updated: February 22, 2009 13:00 EST