"Shown to inhibit and prevent infection of Bird Flu Virus," claimed the website of Long Beach-based PRB Pharmaceuticals Inc. about its drug Vira 38.
"Guard Yourself Against The Deadly Avian Flu Now!" advised Vitacost.com Inc. of Boynton Beach, Fla., regarding its supplements.
"The Body's First Line of Defense Against The Avian Flu -- As Seen on TV!!" trumpeted Bodestore.com about Lingoji, which is made from mushrooms and berries.
It's been a banner season for unproven influenza remedies. Each fall and winter, the Internet abounds with offers of face masks, creams and pills -- all touted as effective flu fighters -- that have escaped the notice of mainstream science. This year, miraculous, anti-flu nostrums seem to have proliferated even more wildly.
Small wonder. Bird flu has been a mainstay in headlines. The seasonal flu arrived earlier than usual in some spots, including Los Angeles County. And "pandemic" has become one of the top words looked up by readers of online dictionaries.
So irritated has the Food and Drug Administration grown that it decided to clamp down on some of the flu claims. Last month, the agency warned PRB Pharmaceuticals, Vitacost, Bodestore and six other companies to stop making claims about avian flu and other forms of influenza or face possible seizure of their products.
Shortly before the FDA move, four leading trade associations for herbal and nutritional products also issued an alert about bogus flu product claims.
"Consumers should be cautious. There are some unscrupulous players out there," said Steven Mister, president of the Council for Responsible Nutrition, which represents supplement manufacturers. "We are not aware of any products that can treat or cure avian flu."
Many infectious disease experts scoff at the idea of supplements as flu-fighting wonders.
Dr. William Schaffner, chairman of preventive medicine at Vanderbilt University in Nashville, said boasts about products that cure or prevent any kind of flu are unproven at best.
At worst, he said, they can be dangerous.
"There are no standards for any of these products," Schaffner said. "There have been times when such products have been contaminated with material that has made them toxic, such as lead.... I'm afraid it's caveat emptor, buyer beware."
Some of the companies warned by the FDA have removed the flu claims from their sites. But some consumers are convinced that daily supplements, which can cost $1 to $2 per capsule, can prevent or treat the flu. Shortages of prescription antiviral medications for the flu may have added to the supplements' appeal.
A little more than a year ago, Danee Shaheen of West Los Angeles had been fighting an uphill battle against what she said was a lingering flu. For days she had felt feverish, weak and congested. Then an acquaintance suggested Immunocil, a nutritional supplement at one time promoted as a way to treat or prevent seasonal or bird flu.
Just 48 hours later, she says, she was cured.
"It killed all those symptoms," said Shaheen, a 72-year-old court reporter. "It seems to work -- unless it's mind over matter."
Immunocil, produced by Westlake Village-based Polycil Health Inc., has been offered as an alternative to vaccination, the preventive treatment with well-established scientific credentials. Shaheen was so satisfied with Immunocil that she skipped her flu shot this season and said she believes the supplement will help if a bird flu pandemic strikes.
Polycil was one of the companies warned by the FDA to stop making such claims.
The company's chief executive, Paul Benveniste, said recently that Polycil had stopped selling Immunocil for a new product that includes the same active ingredient, humic acid.
Dr. Allen S. Josephs, president of Vitacost.com, acknowledged that his website may have overhyped the products and said that it has now removed references to bird flu. "We understand the sensitivity of this matter," he said.
But Josephs said although his products do not prevent the flu, the FDA "doesn't even want you to infer that building your immune system is a way to offset the effects of the avian flu."
Germ-fighting claims extend beyond supplements.
Flufront, a skin cream produced by Charlotte, N.C.-based Jayne Tyler Inc., is fortified with vitamins, minerals and herbs. The product brochure says the cream can "fight off environmental impurities bolstering the immune system's ability to ward off airborne germs and infections." As an added advantage, the brochure says, Flufront softens the skin.
"I'm 59 and I have abused my body -- I used to smoke and get bronchitis a lot," Maxine Bartlett, a real estate agent in Charlotte, said in an interview. "I use Flufront two or three times a day, I put it on my chest or neck, and it works. I haven't been sick all season."
Flufront's maker issued no claims about bird flu, but Bartlett said the cream has eased her fears about a bird flu pandemic.
"Anything we can do to help build up our immune system is great," she said.
Some of the active ingredients of such products have shown medicinal effects. Humic acid in Immunocil demonstrates antiviral properties in lab tests, and lysine, an amino acid used in Flufront, can help prevent or heal cold sores.
But scientific evidence on whether such products boost immune response, or relieve or prevent any type of flu, are "nonexistent, spare or conflicting," Schaffner said.
"All of us would like to believe that there is a nostrum, a miracle ingredient that would either prevent everything or cure everything," he said. "In God we trust. All others must provide data."
Online offerings of flu cures seem to be fueled in part by the spread of bird flu worldwide in recent months. The H5N1 strain circulating in Asia, Siberia and Europe is still primarily a disease of birds; fewer than 150 people have caught it in the last two years, according to the World Health Organization. But the strain has shown alarming lethality -- at least 73 of the victims have died. Scientists fear that if the virus mutates into a form passed easily between people, it could spark a pandemic.
The virus has not surfaced anywhere in this country, although experts believe it could eventually be carried here by migratory birds, smuggled poultry or infected travelers.
"With bird flu, and with the heightened concern that the government has and the public has, we aren't going to put up with any fraudulent claims," said David Elder, director of the FDA office of enforcement.
The government has its work cut out for it. Many bogus or dubious products have emerged of late -- just as they did during the anthrax scare of 2001 and the SARS outbreak of 2003.
In December, San Francisco customs officials seized about 2,500 vitamin C capsules labeled as "generic Tamiflu" -- a prescription drug regarded as effective against bird flu by most scientists. There is no generic version of Tamiflu, which has been in short supply worldwide.
Scores of other products that purportedly cure or prevent flu are also available, especially online. For sale on EBay are virus filters to insert into the nostrils, ear thermometers (whose bird flu-fighting properties are not noted) and full-body disposable protective suits.
Several face masks sold on EBay suggest protection against H5N1. None is approved for that purpose by the FDA. Most do little to keep a person from breathing in viruses, although they may help prevent a sick person from infecting others, Schaffner said.
Air purifiers are also sold as bird flu precautions. Some models can kill viruses, but studies have shown that they would not be able to purify the air in an entire room, let alone a house, said Dr. Laurene Mascola, chief of the acute communicable disease unit for the Los Angeles County Department of Public Health.
"When a person sneezes in your house, some viral particles will travel through every room," she said. Infectious droplets settle on tabletops or other objects.
Public health officials urge people to get a flu shot, wash their hands frequently and get plenty of sleep to avoid seasonal flu.
But purveyors of purported flu remedies are betting that consumers will continue to hedge their bets. One EBay vendor is offering a reservation to buy a survival kit consisting of unspecified gear at an unspecified date if a pandemic erupts.
Although the actual survival kit is not included, at just $1.99 per reservation, it's a bargain.