Fluzone, Flucelvax, FluMist
The flu vaccine is given to lower your risk of getting the flu from the influenza virus. There are multiple types of flu vaccines available, including high-dose flu shots for older adults (e.g. Fluzone High-Dose Quadrivalent), egg-free flu shots (Flucelvax Quadrivalent), and a nasal spray flu vaccine (e.g. FluMist Quadrivalent). Most people should get a flu vaccine every year. The effectiveness of flu vaccine changes from year to year because the influenza virus itself changes over time. General side effects for the flu shot include pain at the injection site, headache, and muscle aches. Side effects from the nasal flu vaccine include stuffy nose and sore throat.
What is Flu vaccine?
What is Flu vaccine used for?
- Flu prevention
How Flu vaccine works
The flu vaccine is a vaccine that protects you from the flu (influenza). The vaccine helps your body's immune system remember the virus so it can attack the virus if it ever infects your body again. There are multiple types of flu vaccine, including:
- Live attenuated influenza vaccine (LAIV) that's made from a weakened form of the live virus
- Inactivated influenza vaccine (IIV) that's made from the dead virus
- Recombinant influenza vaccine (RIV) that's made from a lab-made virus
Drug facts
More on Flu vaccine essentials
Side effects of Flu vaccine
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
- Pain, redness, swelling where flu vaccine was injected
- Weakness or tiredness
- Muscle aches
- Fever
- Headache
- Runny nose
- Nasal congestion
- Wheezing
- Headache
Less Common Side Effects
Flu shot:
- Fainting
Nasal spray flu vaccine
- Vomiting
- Muscle aches
- Fever
- Sore throat
- Cough
Please note: The likelihood of these side effects can differ depending on which type of flu vaccine you've received and your age.
Flu vaccine serious side effects
Contact your healthcare provider immediately if you experience any of the following.
- Allergic reaction: trouble breathing, wheezing, swelling around the lips or eyes, hives, dizziness or fast heartbeat
Pros and cons of Flu vaccine
Pros
- Can lower your risk of the flu by 40-60%
- Free and low-cost vaccine options available (even if you don't have insurance)
- Nasal spray version available for people who don't like needles
- Egg-free versions available for those with egg allergies
Cons
- Hard to predict exactly how well it'll work from year to year
- Can cause side effects such as headaches and body aches
- Can take up to two weeks before you're fully protected from the flu
- Need to get a new flu vaccine every year
Pharmacist tips for Flu vaccine
- The flu vaccine takes 2 weeks to kick in and fully protect you. The CDC recommends getting it no later than the end of October so you are protected before flu season begins.
- Most people will have a sore arm for 1 to 2 days after getting the flu vaccine shot. The best way to prevent this side effect is to move your arm around for a few hours after your shot.
- Redness and warmth in the area where you got the flu vaccine shot are expected side effects. These side effects are temporary and will usually go away within 1 to 2 days. But if your symptoms are bothersome, you can apply an ice pack for about 20 minutes at a time to help with the redness and warmth.
- Although getting the flu vaccine is the best way to prevent getting the flu, there are other steps you can take to protect yourself and those around you. Avoid close contact with sick people, wash your hands frequently with soap & water for 20 seconds, cover your mouth and nose when you cough or sneeze, and disinfect commonly touched surfaces.
- After receiving the flu vaccine, some people start to feel like they are getting sick. Things like muscle aches, headaches, and a low-grade fever (between 99.5 and 100.3 degress Fahrenheit) are normal side effects of the vaccine. This will usually get better within 1 to 2 days after receiving the flu vaccine. Call your healthcare provider if your fever is higher than 100.5 degrees Fahrenheit or if these symptoms last longer than 3 days.
- If you have an allergy to eggs, be sure to let the pharmacist or healthcare provider giving you the flu vaccine know this. Some versions of the flu vaccine are made using eggs and can cause an allergic reaction. You will need to receive a vaccine made without eggs. If you had a life-threatening allergic reaction to eggs (trouble breathing, throat closing), please speak with your healthcare provider before getting the flu vaccine.
Common questions about Flu vaccine
No, you can't get the flu from the flu vaccine. Flu vaccines are made with dead or weakened viruses that can't cause an infection. However, some people might experience flu-like symptoms, such as headache or body aches, after getting a flu vaccine. These symptoms might be caused by a few reasons: (1) One possibility is that these are side effects from the flu vaccine. If so, the symptoms should get better in a couple of days. (2) Another possibility is that you got sick from another virus that causes similar symptoms as the flu. (3) A third possibility is that you caught the flu. This can happen if you were exposed to the flu virus before your body was able to build up full protection against the virus after the flu vaccine (which typically takes about 2 weeks).
It's tough to say how well the flu vaccine will work before the flu season starts. This is because researchers can predict, but won't know for sure, how the flu virus will change and spread each year. In general, flu vaccines can protect you against the flu 40-60% of the time. Keep in mind that there are multiple types of flu vaccine and some are recommended for certain groups of people. For example, the high-dose flu shot (Fluzone High-Dose Quadrivalent) is one of the vaccines specifically recommended for older adults because it can help older adults build better protection against the flu virus. Ask your provider if you've any questions about how well the flu vaccine works and whether a particular one is recommended for you.
Your protection from the flu vaccine lasts about a year. This is because the flu virus changes year to year, so the vaccine and its protection against the virus changes year to year.
You can still get the flu vaccine when you're sick only if you have mild symptoms, like a low-grade fever, slight cough, or runny nose. But if your illness symptoms are moderate or severe, your provider will likely ask you to wait before getting the flu vaccine. If you're not sure if you can receive a flu vaccine, just ask your provider.
Let your provider know if you have an egg-allergy. Many flu vaccines are made using viruses grown in eggs, so there's a risk that these vaccines can cause an allergic reaction in people with an egg-allergy. However, there are a few flu vaccines that aren't made using eggs and are possible options for people who are allergic to eggs. Egg-free flu vaccines include Flucelvax Quadrivalent (for people 6 months and older) and Flublok Quadrivalent (for people 18 years and older)
The CDC recommends that people age 65 years and older receive a flu vaccine that can help better protect them against the flu virus. A high-dose flu vaccine (Fluzone High-Dose Quadrivalent) is one possible option for older adults. The other options include Flublok Quadrivalent and Fluad Quadrivalent, which are also made to trigger stronger protection against the virus. If your local clinic or pharmacy don't have these flu vaccines in stock, you're recommended to get a standard-dose flu vaccine instead.
Yes. If you're due for both, it's safe to get the flu vaccine and the COVID vaccine at the same time. This way, you won't need to make two separate vaccine appointments.
Yes, you're recommended to get the flu vaccine if you're pregnant. This is because getting sick with the flu while pregnant can be dangerous to both the mother and her unborn child. But, you shouldn't get the nasal spray flu vaccine since experts don't know how it affects unborn babies.
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Risks and warnings for Flu vaccine
Flu vaccine can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Life-threatening allergic reactions
- Risk factors: People with egg allergies | History of allergic reactions to a previous flu vaccine
As with any medication or vaccination, it's possible to have an allergic reaction to the flu vaccine. While very rare, an allergy to the flu vaccine could cause swelling of the lips and tongue, cause trouble breathing, or cause your throat to close (anaphylaxis). These reactions are life-threatening. Less severe reactions include hives or a rash. If you are allergic to eggs or egg proteins, be sure to request a flu vaccine made without eggs (called a cell-based flu vaccine) to help prevent any reactions. If you've ever had an allergic reaction to any vaccine, discuss whether you should receive the flu vaccine with your healthcare provider.
Guillain-Barré syndrome
- Risk factors: People who have had GBS in the past | People over age 50
Though rare, there have been reports of people developing Guillain-Barré syndrome (GBS) after receiving flu vaccine. GBS is a rare condition that causes muscle weakness and paralysis. It typically gets better on its own within a few weeks, but some people have long-term problems from GBS. If you have had GBS in the past, especially if you developed it within 6 weeks of getting a vaccine, please talk to your healthcare provider before getting the flu vaccine.
Weakened immune system
- Risk factors: Conditions that weaken the immune system | Taking medications that weaken the immune system
The flu vaccine might work as well if you have a weakened immune system or take medications that weaken your immune system (steroids, chemotherapy). Discuss with your healthcare provider if you should receive the flu vaccine if you have a weak immune system. If you are supposed to get the flu vaccine, be sure to get an inactivated vaccine (made with dead viruses). The nasal spray flu vaccine contains live viruses and should be avoided if you have a weakened immune system.
Won't protect against all flu viruses
The flu vaccine will only protect you against flu viruses 40% to 60% of the time. It won't be able to protect you from all strains of the flu. You're recommended to continue safe practices, such as staying away from people who are showing flu-like symptoms and washing your hands with soap and water before eating.
Severe wheezing requiring hospitalization (nasal spray only)
- Risk factors: Children under 2 | Children under 5 years with a history of wheezing | People with asthma
The nasal spray flu vaccine can cause certain people to have severe wheezing that leads to a hospital stay. Children under 2 years old, children under 5 years old with a history of wheezing, and people who have asthma have a higher risk of this. These groups of people should only receive the injectable flu vaccine, because it's not known to cause severe wheezing.
Flu vaccine dosage
Typical dosage for Flu vaccine
There are many different flu vaccines, so talk with your provider about which one is best for you. A few examples of common flu vaccines include:
*Standard-dose flu vaccine shots *
- Fluarix Quadrivalent, Fluzone Quadrivalent (for people age 6 months and older): The typical dose is to receive one injection in the arm muscle once a year. Younger children receiving flu vaccine for the first time might need two doses, given a month apart.
High-dose flu vaccine shots
- Fluzone High-Dose Quadrivalent (for people age 65 years and older): The typical dose is to receive one injection in the arm muscle with a needle once a year.
Nasal flu vaccine
- FluMist Quadrivalent (for people age 2 to 49 years old): The typical dose is to receive 1 spray in each nostril once a year. Younger children might need two doses, given a month apart.
Flu vaccine contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Flu vaccine will not be safe for you to take.
- History of severe allergic reaction (e.g., anaphylaxis) to the flu vaccine
