MONDAY, Jan. 10 (HealthDay News) -- The H1N1 swine flu pandemic last winter offers clues about how to create a vaccine that can protect people against multiple strains of influenza, U.S. researchers say.

They found that people who were infected with the H1N1 virus and recovered had a special immune response, producing antibodies that protect against a wide variety of flu strains.

The virus matched typical influenza strains only in components that are vital for the virus to function, and the immune response to those components overlapped prior influenza exposures, explained the research team, from the University of Chicago and Emory University in Atlanta.

Creating a vaccine that triggers an immune response against these critical flu virus components, they said, could eliminate the need to predict seasonal flu strains and quickly mass-produce a vaccine every year.

The finding is "something like the Holy Grail for flu vaccine research," according to Patrick Wilson, an assistant professor of medicine at the University of Chicago.

"It demonstrates how to make a single vaccine that could potentially provide immunity to all influenza," Wilson said in a University of Chicago Medical Center news release. "The surprise was that such a very difficult influenza strain, as opposed to the most common strains, could lead us to something so widely applicable."

The study was published in the Jan. 10 issue of the Journal of Experimental Medicine.

The H1N1 flu pandemic during the winter of 2009-2010 infected about 60 million people and led to the hospitalization of more than 250,000 people in the United States.

More information

The U.S. National Institute of Allergy and Infectious Diseases has more about influenza.