Flu vaccine effectiveness of 47 percent means you are half as likely to come down with the flu this season if you have been immunized. But even if you come down with the flu, the flu vaccine can still offer protection.
This year's flu vaccine is especially effective in children, at 61 percent. Experts said even if the vaccine is not a perfect match, the vaccine can still help lessen the severity of the flu, and reduce the chance of experiencing severe complications. Getting a vaccine also can reduce the length of the flu if you do get sick.