Can you get the flu from a flut shot?
Dr. Devin Minior is a physician at Banner Goldfield Medical center. For more information on this topic, talk with your doctor.
Question: Someone told me I can't get the flu from a flu shot, but I was sick the next day. Was I the exception?
Answer: The influenza vaccine, commonly called a "flu shot," is the best way to protect against influenza, a very serious illness. Before each annual flu season, which typically spans from October to May, a vaccine is developed based on research that identifies which strains of influenza are anticipated for that year.
When people get vaccinated for influenza, their immune systems create antibodies to fight the illness. These antibodies protect against future exposure to certain influenza viruses. These protective antibodies do not develop for about two weeks after receiving a flu shot. Therefore exposure to influenza before the antibodies have developed could result in an influenza illness.
The flu shot itself cannot give someone influenza because the vaccine does not contain a live virus. This means the actual flu is not injected into the body. However, the body responds to the vaccine in the same way as if it was the actual live virus. Because of this, about 20 percent of people who receive the vaccine may feel achy for 24 hours or less. This is a reaction to the vaccine and not influenza.
Since the body's immune system has to work hard to develop antibodies, a person who has a fever from a separate infection (for example a cold), should not receive the flu vaccine until the fever has resolved.
Finally, while the flu vaccine is designed to protect against the most common types of influenza in a given season, it is possible - though not typical - to still get influenza. No vaccine is one hundred percent foolproof. Age and health history are both factors in an individual’s response to the vaccine. However, if you do get the vaccine and still get influenza, the illness is typically much less severe than if you had not received the vaccine. Though everyone is different, the vast majority of people will not get sick due to a flu shot. For most people, the preventive benefits of the influenza vaccine far outweigh any possible negative effects.