A Answers (7)
Mehmet Oz, MD, Cardiology, answeredYou know the flu shot can help prevent a nasty case of the flu -- but can it also give you the flu? In this video, Dr. Oz explores this common misconception.
Stacy Wiegman, PharmD, Pharmacy, answeredYou cannot get influenza (the flu) from the influenza vaccine. Viruses used in the vaccines are either dead or extremely weakened. Some of the side effects of influenza vaccines resemble those of influenza. However, these are not an indication that you have the flu.
You cannot get the flu from the flu vaccine. The flu shot contains inactivated (killed) flu viruses that cannot cause illness.
Seasonal flu vaccines have a very good safety track record when it comes to side effects. The Centers for Disease Control and Prevention and the Food and Drug Administration closely monitor the safety of seasonal flu vaccines.
Serious problems from inactivated influenza vaccine are very rare. But there is a possibility for some mid side effects, such as soreness, redness, or swelling where the shot was given; red or itchy eyes, cough, aches, headache, fatigue and sometimes fever.
Elif Oker, MD, Emergency Medicine, answered
No, you cannot get the flu from the flu shot as there is no live virus in the vaccine.
If you experience mild flu like symptoms just after getting the flu shot, this is a sign that your body is building an immune response to the flu.....in other words the flu shot is working!
So you ask how is it you got the flu the last time you got the vaccine? The answer is likely one of three:
1. You didn't get the flu, but another illness.
2. Your vaccine was not 100% effective. The good news here is that most folks who fall into this category have a milder illness then those who did not get vaccinated.
3. You caught the flu in the period before the vaccine became effective. (It takes 2 weeks for the vaccine to kick in after getting the shot.)
A flu shot cannot cause flu illness. The viruses contained in flu shots are inactivated (killed), which means they cannot cause infection.
Flu vaccine manufacturers kill the viruses used in the flu shot during the process of making the vaccine, and batches of flu vaccine are tested to make sure they are safe. In randomized, blinded studies, where some people got flu shots and others got saltwater shots, the only differences in symptoms was increased soreness in the arm and redness at the injection site among people who got the flu shot. There were no differences in terms of body aches, fever, cough, runny nose or sore throat.
The presence of the CDC logo and CDC content on this page should not be construed to imply endorsement by the US Government of any commercial products or services, or to replace the advice of a medical professional. The mark “CDC” is licensed under authority of the PHS.
Flu shots do not give you the flu, or influenza. What flu shots do is train your body to attack the flu. When your body is shown the flu shot, it creates an immune response which is like your body training for fighting off the flu. You may get a slight elevation in temperature and some pain at the site of injection, but it does not give you the flu.
Discovery Health answeredCheck out Dr. Know's explanation about flu shots, which can't really give you the flu. Learn more about influenza in this video from Discovery.