Dear Science,

Should I get a flu vaccine this year? I'm 22 and have never had the flu. The shot hurts like hell, right? My shitty job doesn't have health insurance, and I can't be off work for long without getting into deep money trouble. Is this all a bunch of bullshit? Will the world end or will it just be another winter with regular sorts of colds? My friend who read The Great Influenza is begging me to get the shot. Science, help!

Swine-phobic

First, the official line from the CDC: If you're a pregnant woman, a health-care worker, aged 6 months to 24 years old, caring for people under 6 months of age, or with a preexisting disease that makes you likely to die from a lung infection, you should be vaccinated for swine flu. That adds up to about 160 million people in the United States. Sounds reasonable to Science.

The annual flu—the regular old flu we know, love, and have some limited immunity to—serves the following plate: fever, cough, runny nose, headaches, and body aches. These are not subtle symptoms. Expect a decent fever, above 100 or so (38 centigrade for the educated). The body aches can feel like knives being inserted into all of your muscles. (If you don't have the above, you probably don't have the flu. Don't go to the doctor. Don't go to the ER. Sit at home. Eat chicken soup. Going to the ER in the next few months is likely to get you the flu.) Swine flu has all of the above, plus diarrhea and vomiting. Why? Because when it hurts to move, the best thing to have is an uncontrollable urge to barf.

Every summer, the epidemiologists and virologists get together and attempt to figure out the flu variants most likely to be running around the globe in the coming fall. The flu vaccine comes in two forms: a shot from flu virus grown in eggs then killed with detergent, and an inhaled mist (no needle required) that is an attenuated version of the same candidate flu viruses. (Attenuated means "broken at making you sick" in vaccine land.) You can expect some soreness and maybe a day or two of low fever as the vaccine does its job in getting your immune system all worked up.

Nobody really knows how bad this year's flu season is going to be. Most docs and scientists are worried about swine flu because it's so different than the annual influenza most of us have seen; our immune systems are totally unacquainted. Recent studies published in the New England Journal of Medicine have shown several of the candidate swine-flu vaccines get our immune systems at least ready to put up a fight. If you're in the groups the CDC is recommending, get vaccinated. It should be available most places early in October.

Immunizingly Yours,

Science

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