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FLU IMMUNIZATION: Myths & Realities


The influenza or flu vaccine is a safe and effective way to help people stay healthy, prevent illness, and even save lives. The influenza virus can cause serious illness and even death in people with certain chronic health conditions. The influenza vaccine is the best protection against influenza illness and its complications.

Many people use the term flu to refer to any illness caused by a virus, such as stomach flu or the common cold. However, the influenza virus causes illness that tends to be more severe than other viruses.

Myth: Influenza is not a serious illness.


Many people have died from influenza or its complications. Influenza can lead to serious illness, especially in those who have weakened or compromised immune systems (i.e. diabetics, seniors over 65 years, etc.)

Myth: I have never had influenza, so I do not need to get the vaccine.


Influenza viruses change or mutate often. Most people can get sick with influenza several times during their lives. An influenza vaccine is the best protection against the influenza virus.

The influenza vaccine can give me influenza.


The influenza vaccine or flu shot given by needle cannot give you influenza. The vaccine contains dead influenza viruses that cannot cause infection. Common reactions to the influenza vaccine or flu shot may include soreness, redness and swelling where the vaccine was given. Other symptoms can include fever, headache and aching muscles that may last 1 to 2 days. A live influenza vaccine that is given as a nasal spray contains weakened influenza viruses and has the potential to cause mild symptoms, such as runny nose, sore throat and fever. As a precaution, some people such as those with severe asthma or weakened immune systems should not get this live vaccine.

Myth: The influenza vaccine causes severe reactions or side effects.


The influenza vaccine is safe. Most people only have redness or soreness where the flu shot was given. Some people, especially those who get the flu shot for the first time, may have muscle aches or tiredness.
People who receive the live influenza vaccine, which is given as a nasal spray, may have a runny nose, nasal congestion or cough. These symptoms are less severe than those from influenza infection and last a shorter time.

Guillain-Barré Syndrome (GBS), a form of paralysis, is usually temporary and can occur after some common infections. GBS may be associated with influenza vaccine in about 1 per million recipients.

Myth: Getting an influenza vaccine every year weakens my immune system.


The influenza vaccine boosts your immune system to protect against the virus. It does not weaken it.

Myth: I should not get the influenza vaccine because I have allergies.


Most people with allergies can get an influenza vaccine without any problems.  However, if you have had a severe allergic reaction to a previous dose of the influenza vaccine or to eggs or any other component of the vaccine, talk to your doctor. You may need to be tested for allergies before being immunized.

Myth: The influenza vaccine protects against the viruses or bacteria that cause colds or stomach illnesses.


The vaccine does not protect against the viruses or bacteria that cause colds or stomach illnesses, often called the stomach flu. The influenza virus is very different and more severe than the common cold or the stomach flu. Influenza vaccine only helps protect against the viruses that cause influenza.

Myth: The vaccine does not work because I still get influenza or the flu.


There are many different types of viruses year-round that can cause flu-like symptoms,  but these are not actually the influenza virus. The influenza vaccine protects against the 3 strains of influenza viruses that health experts believe will likely cause influenza during the flu season. It does not protect against other viruses that cause similar illnesses, like respiratory synctial virus or parainfluenza. Because the influenza virus strains change most years, you need to get the influenza vaccine each year to be protected against new strains. When the strains in the vaccine are well-matched to the strains of influenza virus in the community, the vaccine prevents influenza in more than 7 out of 10 vaccinated persons. In elderly people and people who have certain chronic health conditions, the vaccine may not prevent influenza completely but may decrease symptoms, complications and the risk of death from influenza.

Myth: I am pregnant and should not get the influenza vaccine.


The influenza vaccine is considered safe at any stage of pregnancy. Women in the  second half of pregnancy are at higher risk of hospitalization due to influenza. As well, pregnant women who have certain
chronic medical conditions such as diabetes or asthma or who are health care workers should be immunized at any stage of pregnancy. The safety of the nasal spray influenza vaccine during pregnancy has not been determined; therefore, pregnant women or those intending to become pregnant should receive the influenza vaccine or flu shot given by needle, which contains dead influenza viruses that cannot cause infection.

Mothers with babies and toddlers younger than 2 years should get the influenza vaccine if they have not been immunized during pregnancy. Children under 2 years are at higher risk of hospitalization for influenza. Babies under 6 months cannot be vaccinated because their immune response to the vaccine is not as strong. Vaccination for mothers and household or other contacts, including staff of child care centres, can help protect children too young to be immunized and infants and toddlers who get more ill from influenza than older children.

Myth: I am a nursing mother and should not get the influenza vaccine.


It is safe for babies to breastfeed after mothers receive the influenza vaccine or flu shot. Nursing mothers should receive the influenza vaccine or flu shot given by needle, which contains dead influenza
viruses that cannot cause infection.

Myth: There is a nasal Spray


There is a nasal spray that immunizes against the flu. If you would like this vaccine for your child, please discuss it your health care provider.

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