Yes, and no. The influenza vaccine is made up of the proteins that are contained in the influenza virus, called recombinant influenza vaccine, or an inactivated influenza vaccine, which means it cannot infect anyone. However, because a vaccine is designed to stimulate your immune system to create antibodies against the influenza virus, you may have some of the symptoms of an infection such as mild fever, aches or fatigue. But these symptoms are mild and should not last more than a day or two.
Sometimes, people may have contracted a cold virus coincidentally at around the same time, or the immune reaction itself tricks people into thinking that they contracted the flu. Unfortunately, this then creates the misunderstanding and propagates the misconception of “the last time I got the flu shot, I got the flu.” Finally, although the vaccine is protective against the flu virus, it is not foolproof. Scientists make their best estimation on which flu strain is likely to come around and create the vaccine around this estimation.
Because of that, a strain that is not expected may still cause individuals who have had the vaccine, to get the flu. However, the antibodies from the vaccine are enough to allow people who received the vaccine to fight off the flu very quickly. So rather than being ill for a week, you may only be ill for a couple of days. And especially in people who are at highest risk for complications from the flu, such as the elderly or very young, it can in fact be life saving!
We all can do our part in minimizing the risk to ourselves and to our loved ones by decreasing the risk of catching and spreading the flu virus by receiving the vaccine. And it absolutely benefits those that cannot get the vaccine because of severe allergies, or if they have certain medical conditions, by making sure that those who may be in contact with them are way less likely to have the flu virus themselves.