Does the flu vaccine give you the flu?

iStock_000030133532MediumIt’s a refrain I hear often this time of year.

No, I won’t get the flu shot/vaccine. It gives me the flu.


I’m worried about getting the flu vaccine. I heard it could give you the flu. I’d rather just take my chances. I cannot afford to miss school/work.

Here’s why you might feel like this myth is true:

  • It takes 2 weeks after receiving the flu vaccine to develop the appropriate antibodies. In the meantime, if you are exposed to the flu virus before getting the vaccine, you could potentially come down with the flu during that window of 2 weeks. So, your natural inclination is to think the flu vaccine was the cause. This is a good reason to get your flu vaccine as soon as possible, before flu season is in flu swing.
  • You might come down with the “stomach flu” aka gastroenteritis, where the predominant symptoms are vomiting and diarrhea. This is NOT the same as the flu (influenza) which is what the seasonal flu vaccine protects against. The flu causes sudden onset of high fever, muscle aches, fatigue, headache, cough, and congestion. Remember, that this is the season for many viral infections. Not just the flu. Coming down with the “stomach flu” in close proximity to receiving the flu vaccine is coincidental. Wash your hands well and regularly, particularly when leaving public places during cold and flu season.

Here’s why this myth is a scientific impossibility:

  • The flu shot is a dead virus. It cannot replicate in your body and cause the flu. It just can’t.
  • The flu nasal spray (flumist) is a weakened virus. It cannot replicate in the lungs and cause disease. It can cause mild nasal congestion. But not the flu.
  • So, while you may feel like you’ve experienced the flu after receiving the flu vaccine; it is most likely due to one of the above reasons.

All the more reason to get you and your family protected against the seasonal flu now. Well before we all find ourselves in the thick of flu season.

More information on the flu and flu vaccines:
CDC: Misconceptions about Seasonal Flu and Flu Vaccines
AAP: Debunking 5 myths about the Flu
Mayo Clinic: Influenza (Flu) Symptoms
CDC: 2014-2015 Flu Season


One Response to Does the flu vaccine give you the flu?
  1. Gretchen LaSalle, MD
    February 16, 2016 | 6:13 am

    Thanks for getting this out there! As a family physician, I am right there with you, fighting the good fight to promote vaccinations to both my pediatric and adult patients. I wrote an article called An Ounce of Prevention addressing this issue in the online magazine I would value your feedback!