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.
Flu prevention
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
Source: DailyMed
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
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
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.
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.
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.
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.
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.
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.
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.
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.
History of severe allergic reaction (e.g., anaphylaxis) to the flu vaccine
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