Federal health officials said on Friday that the current flu that is doing the rounds in the U. S. this winter is resistant to the most popular drug, Tamiflu, being used to treat it.

According to the Centers for Disease Control and Prevention, there is no reason to panic although 49 out of 50 trials resisted Tamiflu as it can still be treated with other flu medications.

CDC Director Dr. Julie Gerberding said, "It is still very early in the season. There is very little influenza out there." "This is probably actually not going to affect very many people because we don't use a lot of antiviral drugs in our country," Gerberding said. "Most people with influenza don't get any treatment."

In an average year 36,000 Americans die from the flu and three strains of flu circulate in a normal flu season called H1N1, H3N2 and influenza B. The H1N1 strain which mostly comes from Hawaii, Massachusetts and Texas is the strain that is turning up resistant samples. "We can't predict whether or not these strains will end up being the most important strains in this year's flu season. This particular H1N1 could fizzle out," Gerberding said.

Generically known as oseltamivir, the drug Tamiflu is made by Roche AG and Gilead Sciences Inc. and if taken quickly enough is said to both prevent and treat the flu. Relenza, or zanamivir is a drug made by GlaxoSmithKline under license from Australia's Biota Inc. The CDC has recommended that Relenza be used alone or a combination of Tamiflu and an older drug called rimantadine should be used if infection with H1N1 is suspected.

Roche spokesman Terry Hurley said, "It's early in the flu season and flu is unpredictable. Each flu season is unique. There is no guarantee that this situation will continue throughout the flu season. A lot can change. Last year, for example, the season started with the H1N1 virus and switched to H3N2."

Gerberding said that this year's flu vaccine matched the three strains circulating so far very well. She added that she did not think the virus had evolved but it was coincidental that the strain that came up was resistant to the drug. The CDC says there is still time to get a flu shot, as the peak flu season is usually in February.