Virus Might Just "Run its Course" Like Ordinary Flu

WASHINGTON (CBS/AP) -- As the cases of H1N1 virus, commonly called the swine flu, climbed above 150 in the United States, U.S. health officials said the new virus lacks traits found in the deadly 1918 flu strain.

The global flu epidemic early last century was possibly the deadliest outbreak of all time. The virus was an H1N1 strain - different from the H1N1 strain involved in the current outbreak - and struck mostly healthy young adults. Experts estimate it killed about 40 to 50 million people worldwide.

"We do not see the markers for virulence that were seen in the 1918 virus," said Dr. Nancy Cox, the Centers for Disease Control and Prevention flu chief.

There is still is still only one death reported in the United States -- a Mexican toddler, who died while on a trip to Texas.

President Barack Obama says the swine flu might end up running its course "like ordinary flus" but the government is preparing for the worst just in case.

Speaking to reporters after a Cabinet meeting, the president said it is not clear that the flu will be more severe than other flus. But he said the flu is a cause for concern because it is new strain and people have not developed an immunity to it.

Mr. Obama said, "I'm optimistic that we're going to be able to manage this effectively."

Amid the growing concern over the virus, federal officials are also warning Americans of fraudulent H1N1 treatments advertised over the Internet.

Some sites are promoting unauthorized products that claim to diagnose, prevent, treat or cure the flu strain, according the Food and Drug Administration and the Federal Trade Commission.

"The last thing any consumer needs right now is to be conned by someone selling fraudulent flu remedies," said FTC Chairman Jon Leibowitz in a statement.

U.S. authorities pledged to eventually produce enough swine flu vaccine for everyone who needs it but the shots couldn't begin until fall at the earliest.

Within a week, the CDC hopes to send samples of the new virus to manufacturers so they can begin developing a vaccine. But there's no green light yet for actual vaccine production, reports CBS News medical correspondent Dr. Jon LaPook.

"We anticipate that when we decide to manufacture a vaccine, we will have a large quantity of vaccine by the fall," Dr. Richard Besser, acting director of the Centers for Disease Control and Prevention, told CBS News.

Federal officials also tried to reassure the public it's still safe to fly and ride public transportation after Vice President Joe Biden said he wouldn't recommend it to his family.

"There's not an increased risk there," the CDC's Besser said Friday. "If you have the flu or flu-like symptoms, you shouldn't be getting on an airplane or you shouldn't be getting in the subway, but for the general population that's quite fine to do," he said.

On airplanes, air circulates side to side, with air entering the cabin from overhead, circulating across the aircraft and then exiting the cabin near the floor, reports CBS News correspondent Bianca Solorzano.

"The air goes out the sides of the plane and up through HEPA filters, which are hospital filters. The air on a plane is cleaner than the air in my building," Roger Dow, president of the U.S. Travel Association, told CBS News.

Despite assurances that air travel was safe, Houston-based Continental Airlines, which has over 500 flights per week between the U.S. and Mexico, became the first U.S. carrier to curtail service. Many travelers have become increasingly concerned about going to Mexico, though authorities there said new cases and the death rate was leveling off.