8 FluMist Side Effects You Should Know About (and How to Manage Them)
Key takeaways:
FluMist is a flu vaccine given as a nasal spray. It can cause a few different side effects compared to “traditional” vaccine shots.
Common FluMist side effects include runny or stuffy nose, fever, and sore throat. These are most likely to happen within 1 to 2 days after receiving the vaccine.
Most side effects caused by FluMist can be managed at home. In very rare cases, the vaccine can cause serious side effects.
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Table of contents
FluMist is a flu vaccine that’s approved for people ages 2 to 49 years old. It’s a bit different from other flu vaccines. Unlike traditional flu shots, FluMist is given as a nasal spray. You’ll receive one or two doses, depending on your vaccination history. But what about side effects?
Some FluMist side effects, like fever and headache, overlap with those caused by flu shots. But because it’s a nasal spray, side effects like stuffy nose and sore throat are possible, too. You or your child might feel under the weather for a few days after receiving Flumist, but it beats having the flu.
So, what else might you expect after getting a dose? Let’s discuss.
1. Nasal side effects
Nasal side effects — particularly runny or stuffy nose — are the most common side effects reported with FluMist. And they’re unique to FluMist compared to the shot. Nasal side effects can be a sign that your immune system is responding to the vaccine.
Nasal side effects are most likely to occur within a few days after getting a dose of FluMist. They typically go away on their own within a few days. Children receiving two doses may be more likely to experience nasal side effects after the first dose compared to the second dose.
Contact your healthcare provider if you experience a runny or stuffy nose that doesn’t go away after a week. This is especially the case if you have other symptoms, such as weakness or fatigue. It’s possible that something other than FluMist, such as an infection, is causing your symptoms.
2. Fever
You may experience a fever after receiving FluMist. This side effect was somewhat common in clinical studies. And children were more likely to experience fever compared to adults. Fever is also common after the flu shot.
Like nasal side effects, a fever may be a sign that FluMist is working. In this case, it should go away after a day or two. If it’s bothersome, your healthcare provider may recommend taking a medication like acetaminophen (Tylenol) to help. They’ll also likely suggest you drink plenty of fluids to avoid dehydration.
However, fever can also be a symptom of an infection — including the flu. If your fever lasts more than a few days after your dose, it may be from an infection rather than the vaccine. If this happens with your child, sore throat and cough might also suggest it’s the flu.
Contact a healthcare provider if you or your child’s fever is high, lasts longer than a few days, and/or is accompanied by other symptoms (like cough, skin rash).
3. Sore throat
Among adults, sore throat was one of the most common side effects reported after receiving FluMist in clinical trials. This side effect was also reported in children, but it wasn’t as common.
Like most other FluMist side effects, a sore throat is usually short-lived and goes away on its own. If it becomes bothersome, your healthcare provider may suggest over-the-counter (OTC) pain relievers or throat lozenges to provide some relief.
Similar to fever, a sore throat that doesn’t go away after a few days may be a sign of an infection. If this is the case, or if your sore throat is severe, contact your healthcare provider.
4. Headache
Headache is a common flu vaccine side effect — FluMist included. Adults are more likely to experience a headache after getting FluMist compared to children. This usually starts shortly after receiving the vaccine and should go away on its own quickly.
Even if it’s mild, a headache can be unpleasant. If it’s safe for you to take, your healthcare provider may recommend a medication like acetaminophen or ibuprofen (Advil, Motrin) to help. But let them know if your headache lasts more than a few days or doesn’t go away with treatment.
5. Decreased appetite
Decreased appetite is a possible side effect with FluMist. This was more commonly reported among children ages 2 to 6 years compared to older children or adults.
Keep in mind that appetite loss could also be a sign of the flu (or another infection). Contact your healthcare provider if this lasts longer than a few days, or if it’s accompanied by other symptoms such as fever or sore throat. They may want to order a test to check for an infection.
6. Wheezing
Wheezing (trouble breathing) isn’t common after getting FluMist, but it can happen. For this reason, FluMist should be avoided in children ages 2 to 4 years old with asthma or a history of wheezing. And it should be used with caution in people ages 5 and older with asthma.
FluMist isn’t approved for use in children under 2 years old. This is due to an increased risk of wheezing in clinical trials. Your child’s pediatrician can recommend safe flu vaccines if your child can’t receive FluMist.
If you or your child experience wheezing after getting FluMist, contact your healthcare provider right away. But if your symptoms feel life-threatening, call 911 or go to the closest emergency room.
7. Allergic reactions
While rare, allergic reactions to FluMist are possible. Allergic reactions to FluMist may be mild, such as skin rash or hives. But they can also include serious reactions such as anaphylaxis.
FluMist is made using egg proteins, so you shouldn’t receive it if you have an egg allergy. Instead, talk to your healthcare provider about flu shots that are safe for people with an egg allergy. You also shouldn’t get FluMist if you’ve had a severe allergic reaction to a flu shot in the past.
After getting your FluMist dose, you may be asked to stick around for 15 to 30 minutes in case you develop an allergic reaction. The vaccination site should have medications on hand to treat you in case this happens.
It’s possible to develop symptoms of an allergic reaction after leaving the vaccination site. This may include shortness of breath and swelling of the face, tongue, or throat. If you do, seek urgent medical attention.
8. Guillain-Barré syndrome
Guillain-Barré syndrome (GBS) is a rare autoimmune condition that has been linked to the flu vaccine. However, the risk of developing GBS from the flu vaccine is very small. What’s more, GBS is more likely after getting the flu compared to the vaccine.
Symptoms of GBS can include muscle weakness, tingling, and pain. It can sometimes lead to paralysis. Long-term nerve damage is possible, but most people are able to recover from GBS.
Contact your healthcare provider right away after receiving FluMist if you’re experiencing symptoms like:
Weakness in your legs, arms, or face
Burning, tingling, or “pins and needles” sensation in your hands or feet
Loss of sensation through your skin
Muscle and/or joint pain
When should I contact my healthcare provider about FluMist side effects?
Contact your healthcare provider if any FlluMist side effects are interfering with your work or daily life, or if they don’t go away on their own after a few days. But if any side effects feel life-threatening, call 911 or go to the closest emergency room.
If you’re getting your child vaccinated, reach out to their pediatrician in advance. They can give you helpful tips for how to prepare for the vaccine and manage potential side effects.
The bottom line
FluMist is a nasal flu vaccine that can cause some side effects that are similar to traditional flu shots. But it can also cause nasal side effects and sore throat, too. As with most flu vaccine side effects, these are usually mild and short lived.
Let your healthcare provider know if any FluMist side effects get worse or don’t go away after a few days. If you think you’re experiencing an allergic reaction to FluMist, seek medical attention right away. While rare, this can be life-threatening.
While FluMist can be a needle-free option, it’s not for everyone. Talk with your healthcare provider about which flu vaccine is right for you.
Why trust our experts?
References
Centers for Disease Control and Prevention. (2022). Key facts about seasonal flu vaccine.
Centers for Disease Control and Prevention. (2023). Explaining how vaccines work.
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