What is the flu vaccine?
The flu vaccine is administered annually to help protect you from contracting and spreading the flu. The Centers for Disease Control and Prevention (CDC), the U.S. Food and Drug Administration (FDA), and the World Health Organization (WHO) conduct year-round, global surveillance on circulating flu strains in order to select the flu strains that are included in the flu vaccine each year.
Why should I get the flu vaccine?
An annual flu vaccination can help prevent the spread of influenza between individuals and may help save the lives of those most at risk for severe and fatal complications from the flu. For this reason, the flu vaccine remains the CDC’s top recommendation for influenza prevention for everyone 6 months of age and older.
Is the flu vaccine safe?
Yes. Flu vaccines have been used for more than 50 years with very good safety records. The CDC and the FDA routinely monitor the safety of all vaccines, including the flu vaccine. New vaccines go through years of research and clinical trials before they can be deemed safe and effective by the FDA and made available to the general public.
What are the side effects of the flu vaccine?
Most people who receive the flu vaccine have no reaction. Up to 25 percent may have some redness and slight swelling at the site of injection. Common side effects can include soreness, redness, and/or swelling at the injection site; fever; headache; and/or muscle aches. These common side effects are actually evidence that your body is having an immune response, which is what it’s supposed to do! The risk of a severe allergic reaction in those who are vaccinated is less than one in four million.
Can you get the flu from the flu vaccine?
This is impossible. The flu vaccine contains an inactivated flu virus or no flu virus at all, so it cannot cause the flu.
How effective is the flu vaccine?
The flu vaccine is safe and effective at preventing the spread of influenza, and according to the CDC, an annual vaccine is the first and most important step in protection against the flu.
The flu vaccine was found to prevent death in otherwise healthy children by as much as 65%. When well-matched with circulating flu strains, the flu vaccine has been shown to reduce the risk of flu illness by up to 60%. Even if the flu vaccine is not well-matched to the circulating flu strains for a given year, it still can offer some protection by making flu symptoms less severe.
Who should get vaccinated against the flu? Do healthy people need a flu vaccine?
The flu does not discriminate and can be a potentially serious, even deadly, disease for anyone, regardless of age or health status. The CDC recommends that everyone 6 months and older get vaccinated against the flu every year. This recommendation is the same even during years when the vaccine composition (the viruses the vaccine protects against) remains unchanged from the previous season.
Getting vaccinated not only protects you, but also protects your loved ones and your community (including infants who can’t be vaccinated and people with compromised immune systems). The more people that are vaccinated, the less chance the flu virus has to spread.
Should pregnant women get the flu vaccine?
Yes. The CDC recommends the flu vaccine for pregnant women as the safest and most important method for protecting a mother and her unborn child from the flu. Pregnant women are at risk for developing serious complications from the flu. Flu shots have been given to millions of pregnant women over many years with a good safety record. Research has found flu vaccination during pregnancy not only offers protection to the mother, but also to the infant for several months following birth.
For additional information on flu vaccination during pregnancy, visit CDC’s website here.
Can I get the flu vaccine if I have an egg allergy?
The CDC recommendations are:
- People with a history of egg allergy who have experienced only hives after exposure to egg should receive the flu vaccine.
- People who report having had reactions to egg involving symptoms other than hives; or who required epinephrine or another emergency medical intervention, may receive a flu vaccination administered in an inpatient or outpatient medical setting, including, but not limited to hospitals, clinics, health departments, and physician offices. Vaccine administration should be supervised by a health care provider who is able to recognize and manage severe allergic conditions.
- A previous severe allergic reaction to flu vaccine is a contraindication to future receipt of the vaccine.
Please visit the CDC’s website here for a full explanation of flu vaccination in patients with egg allergies.
Do children need to receive a flu vaccine?
Yes. Children have the highest chance of getting sick from the flu and often spread germs throughout their communities. During severe flu seasons, approximately 30 percent of school-aged children get sick with flu. Every year in the U.S., children miss approximately 38 million school days due to flu.
Influenza is also one of the leading causes of infectious disease hospitalizations among young children. Approximately 20,000 children under the age of 5 are hospitalized due to the flu each year — that’s enough children to fill 870 average American classrooms. Infants and toddlers are hospitalized as a result of influenza at rates similar to elderly people and at higher rates than people of all other ages.
On average, approximately 100 children die in the U.S. from the flu and its complications every year. More than 1,450 children have lost their lives to flu since 2004; most of whom were not vaccinated and many of whom were otherwise healthy.
The CDC recommends that children aged 6 months through 8 years of age get two doses of flu vaccine, at least one month apart, the first year they are vaccinated against flu. Children who previously received a flu vaccine only need one dose.
How does the flu vaccine work?
The flu vaccine causes your body to produce antibodies (infection-fighting cells) that enable it to fight the virus and prevent infection following exposure. It takes approximately two weeks after vaccination for your body to build up protection against the flu.
What’s in the flu vaccine?
Depending on the manufacturer, there can be different ingredients in a flu vaccine. Here’s a list of some general ingredients that may be found in a flu vaccine:
- Proteins from eggs or animal cells used to grow the flu virus may be present in the vaccine.
- Preservatives may be used in multi-dose flu vaccine vials to prevent contamination by dangerous germs like bacteria and fungi. Thimerosal, which is used as a preservative only in multi-dose flu vaccine vials, contains ethylmercury (not to be confused with the toxic form of mercury called methylmercury, which can be found in certain kinds of fish). Ethylmercury is readily eliminated by the body and does not build up to harmful levels. To learn more about thimerosal, visit the CDC’s website here.
- Adjuvants may be used to stimulate the body’s response to a vaccine. Not all flu vaccines contain adjuvants. Aluminum salts have been used as vaccine adjuvants for decades and been found to be safe. For more information on adjuvants in vaccines, visit the CDC’s website here.
- Stabilizers such as sugars or gelatin may be used to ensure that the vaccine doesn’t lose its effectiveness during transport or storage.
- Antibiotics may be used to prevent contamination by bacteria during the vaccine manufacturing process.
- Inactivating agents are used to inactivate the flu virus that has been harvested from eggs or animal cells. Formaldehyde is an inactivating agent commonly used in flu vaccines. Residual amounts of formaldehyde may be present in a flu vaccine, but the amount is comparable to, or even less than, the amount naturally found in our bodies for human metabolism and building proteins. For more information on formaldehyde in vaccines, visit the Children’s Hospital of Philadelphia’s website here.
Do I need to get a flu vaccination every year?
Yes. The vaccine needs to be given every year. Because flu viruses are constantly changing, flu vaccines may be updated from one season to the next to protect against the most recent and most common circulating flu viruses. In addition, a person’s immune protection from the vaccine declines over time; therefore, annual vaccination is needed for optimal protection.
When is the best time to get vaccinated?
Medical experts recommend that people get their flu vaccine as soon as it becomes available in your community. The flu virus tends to spread from October to May, with most cases occurring in January or February. However, vaccinations can be given at any time during the flu season – even getting a vaccination later in the season (December through March) can still help protect you from influenza.
Where can I get a flu vaccine?
Flu vaccines are readily available in a wide variety of locations, including doctors’ offices, schools, workplaces, supermarkets, pharmacies, health departments and community centers. To find a flu clinic near you, use our flu clinic locator.
Where can I learn more about flu vaccine recommendations?
To learn more about flu vaccine recommendations, visit the CDC’s website at www.cdc.gov/flu.