4. WHAT'S IN A FLU SHOT?
Each shot contains a teeny tiny bit of dead flu virus. The virus is grown in fertilized chicken eggs, then extracted and deactivated with microscopic amounts of formaldehyde. A chemical called octylphenol ethoxylate pulls out even smaller pieces of virus, which helps reduce the chances of side effects. Gelatin holds the virus together and keeps it stable during shipping, and a preservative called thimerosol keeps the vaccine from going bad on the shelf. There’s no reason to be concerned about any of these chemicals; they’re present in such small quantities that your body will barely register them. If you have a life-threatening allergy to gelatin or eggs, talk to your doctor before you get your shot.