The best time to get a flu shot is mid-September through the end of November, before the peak of the influenza season. The amount of antibodies in the body is greatest one or two months after the vaccination, and then gradually declines. The vaccination is made each year so that it contains the influenza virus strains that are expected to cause illness that year. The virus is killed or inactivated, so you can't get the flu from getting a vaccination. However, those allergic to eggs could suffer adverse reactions and should talk to their doctors before getting a flu shot.
Influenza is a respiratory disease, but it affects the entire body.
Symptoms include fever, chills, weakness, loss of appetite, and aching of the head, back, arms and legs. The flu sufferer may also have a sore throat, cough, and nausea. When flu strikes the lungs, the lining of the respiratory tract is damaged. The tissues become swollen and inflamed. Fortunately, the damage is rarely permanent, and most people are back on their feet in a week or two.