"If only this were the case," says Schaffner. Instead, there are hundreds of different types of flu viruses that circulate at any given time, so if you get the flu once, you only have protection from that specific type of flu.
In terms of vaccination, this means that just because you got the flu already, this doesn't meant that you should still get the vaccine. You are still susceptible to other types of flu and the vaccine offers the best, although not full-proof, protection against getting these other strains, Schaffner says.
Verdict: Definitely Not True
As stated above, there are hundreds of different strains of flu virus, and these strains change constantly. Every year, the vaccine is made by selecting the three most common types of virus that are currently circulating.
"That's why we need a new vaccine every year," said Schaffner.
For the same reason that getting the flu in November won't protect you from getting another strain in December, getting the vaccine for the strains of flu circulating in 2010 will not necessarily protect you from the types that will be circulating in 2011.
Scientists are working toward a stronger, more universal vaccine that could be a one-shot deal -- with the occasional booster.
While it's better to get the vaccination before the flu season peaks, that doesn't mean it's too late to protect yourself by vaccinating in January or February or even March.
"Flu peaks in February and early March, so there's still time to get vaccinated," says Schaffner, "but that's why I say jog, don't walk, to the drug store to get vaccinated today."
Verdict: Mostly False
Getting severely chilled to the point of hypothermia can make the immune system less resilient, which may make someone more susceptible to flu, doctors say, but you still have to come into contact with the flu to get the flu – and getting a chill, in and of itself, is not going to do it.
Also, your standard amount of "chill" from a drafty window or going out with wet hair is not going to be enough to predispose you to illness, Schaffner says.
Verdict: The Data Suggest Not
Despite speculation that taking large doses of vitamin C or echnicacea will protect people from flu, the data just aren't there to support them as flu-fighters, Schaffner says. There's some mixed evidence that these supplements will help fight off a cold, but when it comes to flu, these methods "strike out," he says.
Verdict: No, Antiviral Medication Will
While antibiotics are sometimes used to control infection such as pneumonia that can accompany serious bouts of flu, antibiotics cannot treat viral infections like the flu.
Antiviral mediation such as Tamiflu and Relenza can fight off the flu virus, but even these can only shorten the duration of the illness, not resolve it altogether, Horovitz says.
Verdict: Please Don't This old adage may sound nice, but there is "no science to prove that it works," says Dr. Peter Katona, an infectious disease specialist at UCLA Medical Center. "You don't starve a flu, you need food and liquids for both [flu and cold]."