As health departments around the state are urging Utahns to get their seasonal flu shots, researchers in Maryland said they have found no initial evidence that the H1N1 flu will combine with other flu strains to create a nasty "superbug," as many have feared.

Results of a laboratory study released today by the University of Maryland show the H1N1 virus is more communicable than other flu strains when tested on ferrets that were exposed to three different viruses. But researchers said the viruses did not combine within the test ferrets to create a more virulent flu virus. The H1N1 virus did out-compete the other flu strains, and reproduced twice as much in the animals as the other viruses, the study said.

"The H1N1 pandemic virus has a clear biological advantage over the two main seasonal flu strains and all the makings of a virus fully adapted to humans," said virologist Daniel Perez, the lead researcher and program director of the University of Maryland-based Prevention and Control of Avian Influenza Coordinated Agricultural Project.

In a news release, Perez said, "I'm not surprised to find that the pandemic virus is more infectious, simply because it's new, so hosts haven't had a chance to build immunity yet. Meanwhile, the older strains encounter resistance from hosts' immunity to them."

The study is believed to be the first to examine how the H1N1 flu virus interacts with other flu viruses, and the findings were published in an online scientific journal, PLOS Currents.

As scientists were mulling the study Tuesday, President Barack Obama urged all Americans to do their part in responding to a potential H1N1 epidemic by having plans in place to deal with the illness that would allow them to stay at home.

Planning by the federal government, in cooperation with state and local health departments and other government entities, has been driven to some extent by concern about how rapidly the H1N1 virus will spread this fall and how virulent it could become.

A national study released in mid-August showed 58 percent of the 665 physicians surveyed said their level of concern for a worldwide catastrophic pandemic of H1N1 was continuing to rise. Conducted by HCD Research in cooperation with the Muhlenberg College Institute of Public Opinion, the survey has measured physician attitudes on a weekly basis and showed their concern rising from mid-July to mid-August.

Detailed results of that study are available at www.mediacurves.com.

Tom Hudackho, spokesman for the Utah Department of Health, said the Maryland study is so new that local researchers haven't had time to digest the particulars.