July 31, 2009

Calif. H1N1 flu more virulent than Mexican

The California isolate of the pandemic H1N1 virus is more virulent than the Mexico isolate and both are more virulent than seasonal flu, U.S. researchers say.

Juergen Richt of Kansas State University College of Veterinary Medicine and colleagues say establishing animal models for pandemic H1N1 is important because physicians have two types of antiviral medications to treat influenza. One type, adamantine-like drugs, targets the M2 protein; the other type includes drugs like Tamiflu that target the neuraminidase protein.

Richt says that this pandemic H1N1 is already resistant to the M2 inhibitors but still is sensitive to Tamiflu.

Some pandemic flu isolates from humans have now shown resistance to the Tamiflu, Richt says in a statement.

So the big issue now is if these Tamiflu-resistant strains take over, we have no drug to treat infected patients. And because we don't have a vaccine yet in the United States, this might be a problem.