The influenza vaccine is one of the safest and most worthwhile medical tools we have available today.

That said, it’s perfectly understandable to worry about any unforeseen side effects, especially if you’re a parent debating whether to subject your child to yet another painful shot. So let’s take a brief look at the various flu shot reactions that could arise when children get vaccinated.

The Centers for Disease Control and Prevention currently recommends that everyone over the age of six months receive a flu shot. And for the most part, children and adults alike experience the same degree of side effects. But younger children may bear the worst of it, especially if they’re receiving it for the first time.

Flu vaccine Here's what to know about the flu shot's side effects in babies. Karoly Arvai, Reuters

Side effects can include:

  • Soreness, swelling, or itching around the injection site

  • General muscle aches

  • Fever

  • Fatigue

  • Headache

At the rarest end of the spectrum (1 to 2 cases out of a million people vaccinated), the flu shot can potentially cause something called Guillain-Barré syndrome. This autoimmune condition targets the peripheral nervous system, causing symptoms of muscle weakness, tingling leg sensations, and even temporary paralysis that can last for weeks to even years.

This flu season, the CDC has advised that people not turn to the live attenuated influenza vaccine (LAIV), otherwise known as the nasal spray version of the vaccine, but some of its additional side-effects in children under the age of 17 can include:

  • Wheezing

  • Stomach pain, vomiting or diarrhea

  • Runny nose or congestion

Every vaccine also carries the risk of allergy, which can trigger a condition known as anaphylactic shock. Similar to Guillain-Barré, the chances of being severely allergic are exceedingly rare, with only one case per every million vaccinations.  

Really though, most people, young or old, don’t suffer any of these adverse effects. And those who do usually don’t have them for more than 1 or 2 days. And despite the common belief that you can get the flu from being vaccinated, neither version is actually capable of that. Because many of these side effects can resemble flu symptoms, though, that might explain the confusion.

Still, at the end of the day, vaccination is an easy way to keep yourself and your children healthy. After all, the flu causes a lot more pain, suffering and deaths than any of its side effects ever have.

Every year, for instance, it’s estimated the flu sends 20,000 children under the age of 5 to the hospital, and kills anywhere from dozens to over a hundred. The vast majority of deaths and hospitalizations happen in the unvaccinated.