10 Flu Vaccine Side Effects That Are Totally Normal

We said it above, but it’s really worth emphasizing: These side effects tend to be mild and last a few days at most, according to Jan Carney, M.D., M.P.H., associate dean for public health & health policy and professor of medicine at the Larner College of Medicine at the University of Vermont. But if you’re experiencing any worrisome symptoms that don’t resolve on their own within a few days, it’s a good idea to speak with a physician.

Can the flu vaccine make you sick?

Let’s just clear this up now: “You can’t get the flu from the flu vaccine,” Dr. Adalja says. Seriously, this is not a thing that is even remotely possible.

However, in very rare cases, a flu vaccine can cause issues in people with pre-existing medical circumstances. The flu vaccine is safe for most people, but if you have any allergies, like to egg proteins or any other ingredients that could be in the vaccine, such as gelatin, it’s important to speak with your doctor or pharmacist before getting inoculated. “Those with an egg allergy can get the flu vaccine, but need to discuss with their doctor which specific vaccine is right for them,” Dr. Agarwal says.

Overall, the CDC recommends speaking to a health care professional prior to getting a flu vaccine if you meet any of the following criteria:

• You’re allergic to eggs or any other potential vaccine ingredients, such as gelatin.
• You’ve ever had Guillain-Barré Syndrome (more on this below).
• You’ve had a severe allergic reaction to a previous flu vaccine.
• You’re not feeling well.

How do I know if I’m having an allergic reaction to the flu vaccine?

Severe or life-threatening allergic reactions to the flu vaccine are very rare. (One CDC report suggests there are 10 anaphylaxis reactions per 7.4 million doses of the inactivated version of the flu vaccine².) When allergic reactions to the flu vaccine do occur, they happen within minutes to hours after getting the vaccine and are generally mild.

Symptoms of an allergic reaction to the flu vaccine include:

• Skin that looks paler than normal
• Suddenly having reddened, swollen bumps or itchy hives on your skin
• Feeling your heartbeat get faster for no other apparent reasons
• Feeling dizzy or lightheaded
• Having trouble breathing, feeling hoarse, or wheezing
• Feeling super weak

These serious allergic reactions are rare, but again, it’s important to tell your primary care doctor and/or your pharmacist about any allergy you have just to be safe. “If you have a history of allergies, let your physician, nurse practitioner, or pharmacist know in advance,” Dr. Carney says. Typically, these more serious reactions occur in people who are allergic to an ingredient in the vaccine, such as egg protein.

In a very, very small number of cases (just one or two cases for every million people who have been vaccinated), the vaccine can be associated with a rare illness called ​​Guillain-Barré syndrome, in which your immune system attacks nerves within the body. The disease causes muscle weakness and tingling (usually in the legs and feet first) so you could feel a pinprick sensation or notice that you feel unsteady when walking, according to the Mayo Clinic. But try not to let the fear of ​​Guillain-Barré deter you from getting your flu vaccine—the CDC notes that the risk of ​​​Guillain-Barré syndrome is far lower than the risk of having severe complications from the flu.

Can you get the flu vaccine and COVID-19 vaccine or booster at the same time?

“You can get a COVID-19 vaccine and a flu vaccine during the same visit, according to the CDC and based on extensive research with vaccines,” Dr. Carney says. “This gives people the opportunity to get vaccinated for both flu and COVID-19 at the same time, increasing their protection against both of these infections.”