Like other vaccines, flu vaccines can have side effects.
Fortunately, most of those side effects are mild.
What Are the Side Effects of the Flu Vaccine?
Not surprisingly, a lot of things that get blamed as being caused by flu vaccines are not actually side effects.
Did you actually get the flu in the days or weeks after your flu vaccine?
That’s not a side effect of your flu vaccine. Neither the inactivated flu shot, nor the attenuated FluMist can actually cause a flu infection.
Did you get a little sore at the site where you got your flu shot?
That’s a common side effect to getting a flu shot.
So is having some redness and swelling at the site, all of which begin soon after getting the shot and go away in a few days. You can also get a headache, fever, nausea, and muscle aches or signs and symptoms of an allergic reaction.
Do you have a runny nose or a cough? Side effects of the nasal spray flu vaccine can include a few days of runny nose, wheezing, headache, vomiting, muscle aches, fever, sore throat and cough.
Again, a bad cough and cold after a flu shot isn’t a side effect of the vaccine though.
Remember, correlation does not imply causation.
If you found out you were pregnant shortly after getting a flu shot, you wouldn’t think they were associated, would you?
What about narcolepsy?
“An increased risk of narcolepsy was found following vaccination with Pandemrix, a monovalent 2009 H1N1 influenza vaccine that was used in several European countries during the H1N1 influenza pandemic.”
Narcolepsy Following Pandemrix Influenza Vaccination in Europe
Although the focus has been on the Pandemrix flu vaccine as a trigger for narcolepsy in some countries (the vaccine wasn’t used in the United States), interestingly, several countries that weren’t using the vaccine also saw a spike in narcolepsy cases as the 2009 H1N1 pandemic hit.

What about all of the reports of severe reactions and deaths after getting a flu shot that you might hear about? In addition to vaccine injury stories, those reports are to VAERS and typically are not causally related to getting a vaccine.
Why are there so many reports to VAERS and the NVICP about flu vaccines? Since 2006, over 1.6 trillion doses of flu vaccine have been distributed in the United States, which equals about the total of all other vaccines we use.
What Are the Side Effects of This Year’s Flu Shot
Even when folks understand that flu vaccines don’t typically cause serious side effects, the question always comes up whether or not this year’s flu shot is causing more side effects than usual.
That’s actually not unreasonable, even when you consider that the biggest change in most flu vaccines from year to year is the strain of flu viruses they include, and not any of the other ingredients.
In addition to the Pandemrix flu vaccine, in 2010, the use of one brand of flu vaccines in Australia was suspended because they were causing more side effects (fever and febrile seizures) in young children than expected.
“The studies flesh out preliminary findings from CSL in June 2012, which said that the manufacturing process retained more virus component than that of other manufacturers and that the 2010 virus components triggered an excessive immune response in some young kids.”
CSL studies shed light on 2010 flu vaccine seizures
So are there any more side effects this year?
No, there is no evidence of increased side effects from this year’s flu vaccines
More on Flu Vaccine Side Effects
- VAXOPEDIA – I’m Not Anti-Vaccine, I Just Don’t Believe in Flu Shots
- VAXOPEDIA – Can Vaccines Cause Guillain-Barre Syndrome?
- VAXOPEDIA – Can Flu Shots Cause the Flu?
- VAXOPEDIA – Do They Really Just Guess at Which Strain to Put in the Flu Vaccine?
- VAXOPEDIA – Three Reasons to Skip a Flu Shot This Year
- Flu Facts vs. Fiction
- Flu Myth Buster
- The myth of getting the flu from the flu shot
- Everything You Want to Know About Influenza
- Ask the Experts About Flu Vaccines
- CDC – Flu Vaccine Safety Information
- WHO – 5 myths about the flu vaccine
- CDC – Misconceptions about Seasonal Flu and Flu Vaccines
- NHS – Flu vaccine side effects
- WHO – Observed Rate of Vaccine Reactions Influenza Vaccine
- Influenza Vaccine – Adverse Effects of Vaccines
- 32 Myths About The Flu Vaccine You Don’t Need To Fear
- Study – Quantifying benefits and risks of vaccinating Australian children aged six months to four years with trivalent inactivated seasonal influenza vaccine in 2010.
- CSL studies shed light on 2010 flu vaccine seizures
- CDC – Narcolepsy Following Pandemrix Influenza Vaccination in Europe
- WHO – Statement on narcolepsy and vaccination
- A stubborn medical mystery: Was pandemic flu vaccine tied to an increase in narcolepsy cases?
- Vaccine adverse events: causal or coincidental?