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Flu shot myths and facts

October is the start of flu season. As the flu virus starts to circulate, so do questions about flu shots and flu prevention. To clear up some common concerns, Women’s Health Matters spoke to Jessica Ng, manager of infection prevention & control at Women’s College Hospital, about flu vaccine myths and facts.


Myth: The flu shot can give you the flu

Fact: There is simply no truth to this.

“The flu shot doesn’t give you flu,” says Ng. You cannot get the flu from the vaccine. The virus used in the injected vaccine is inactivated, which means it is dead and cannot cause illness.


Myth: The flu is not a serious illness

Fact: Every year, about 20,000 people in Canada are hospitalized with flu, and about 4,000 die from it.

The flu is very serious for high-risk groups: older people, people with pre-existing medical conditions or chronic illnesses, people with compromised immune systems, young children and pregnant women.

“Those are the groups at highest risk, but anyone is at risk of getting flu,” Ng says.

Even young, healthy people can get very sick from the flu. Having the flu also means you can spread the virus to people in your household, workplace or other environments, making them sick, too. Some of these people may be in high-risk groups, even if you are not. You can spread the flu virus before you start seeing flu symptoms.


Myth: I got a flu shot last year, so I don’t need another one

Fact: To be protected, you need to get a flu shot annually.

Different forms of the flu virus circulate every year. Because the virus changes, so does the vaccine: each year, the flu shot is formulated to fight that season’s circulating virus.

“Getting the flu shot allows your body to create antibodies against the flu,” Ng says.


Myth: The flu vaccine is not effective

Fact: “The flu shot is your best line of defence,” Ng says. The vaccine helps your immune system defend your body from the flu virus.

The flu vaccine is the most effective way of preventing flu, but it is not 100 per cent effective. The ability of the flu vaccine to protect a person depends on several factors, including that person’s age and the state of their health, as well as how closely the inactivated virus in the vaccine matches the virus that’s currently circulating. So there is still a chance that a vaccinated person could get flu, but the risk is significantly lower than that of an unvaccinated person. If a vaccinated person does get flu, the illness is likely to be less severe.

It does take a couple of weeks for the vaccine to take effect. That’s why there are cases of people getting the flu shortly after getting their flu shot. It takes about two weeks for the body to begin producing antibodies, so it is still possible to catch the flu virus and become ill during this period. The illness was not caused by the flu shot (see the first Myth, above).


Myth: If I live a healthy lifestyle, I won’t catch flu

Fact: Anyone can catch the flu.

The flu virus is spread through droplets that can travel when an infected person coughs, sneezes or talks. When someone else inhales these droplets, that person can become infected. That’s why flu spreads easily in crowded places such as public transit.

Infected people can also have these droplets on their hands (from covering their mouth when they cough, for example), and may deposit them on surfaces such as doorknobs, handles, elevator buttons and other high-touch surfaces. When others touch these surfaces and then touch their own nose, mouth or eyes, they can become infected.

“That’s why it’s important to clean your hands,” says Ng.


Tips to protect yourself and others from flu:

  • wash your hands often and use hand sanitizer frequently
  • avoid touching your face, especially your nose, mouth and eyes
  • avoid close contact with sick people
  • sneeze or cough into a tissue, or into your elbow or sleeve
  • don’t sneeze or cough on other people
  • stay home if you are sick
  • get a flu shot

For more information or questions about the flu or flu vaccines:

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