WEST LAFAYETTE, Ind., April 18 (UPI) -- A vaccine under development may provide protection against highly pathogenic bird flu and its evolving forms, U.S. researchers suggest.

Researchers at Purdue University and the Centers for Disease Control and Prevention in Atlanta say, unlike traditional influenza vaccines, the new vaccine could be produced quickly and stored for long periods in preparation for a pandemic.

Purdue virologist Suresh Mittal and colleagues have found that the vaccine protected against avian flu H5N1 for a year or longer. Because the studies have only been done in mice, it's not yet known whether the same results will be obtained in humans, Mittal said.

One of the problems with current influenza vaccines is that they are made from eggs, a process that can take as long as six months. But the vaccine Mittal and his research team have developed isn't grown in eggs, making vaccine production much faster.

The new vaccine uses an adjuvant -- molecules added to the vaccine that stimulate the body's immune system -- so lower doses of the vaccine can be used. The adjuvant also allows the vaccine to be stockpiled so more people can be vaccinated, and it helps the vaccine protect against variant forms of the H5N1.

The findings are published in The Journal of Infectious Diseases.