Influenza (Seasonal Flu) and the Influenza Vaccine (Agriflu®,Vaxigrip®, Fluviral®)
What is influenza?
Influenza (the flu) is a serious respiratory illness that is caused by a virus. It spreads in the fall and winter. It causes fever, chills, muscle aches, headache, runny nose, sore throat, cough, weakness and tiredness. Symptoms usually last two to seven days. Cough and weakness may last for up to six weeks. Elderly persons may have the flu without a fever. Children may have stomach symptoms such as nausea, vomiting and diarrhea.
Who is at risk?
Everyone is at risk of getting the flu. Although most people will not get seriously ill, some people may develop flu-related complications such as lung infections (pneumonia), ear infections, dehydration (loss of body fluids) and, in rare cases, death. People most at risk include: children less than five years of age; people 65 years of age and older; residents of long-term care homes or chronic-care facilities; people with chronic health conditions such as diabetes, cancer, obesity, lung, heart or kidney disease; healthy pregnant women; and aboriginal peoples.
How is the flu spread?
You can get the flu if someone who has the flu coughs or sneezes on you. Touching hands, surfaces, or objects that someone with the flu has touched and then touching your eyes, nose or mouth can all lead to getting the flu.
What can I do to prevent the spread of the flu?
Get the flu shot each fall. Also follow these simple steps to protect yourself:
- wash your hands frequently
- cover your cough and sneeze with something other than your hands
- stay home when you are sick
- avoid touching your eyes, nose and mouth with unclean hands
- avoid close contact with persons who are sick with the flu
What is the influenza vaccine and what does it do?
Each year, the influenza vaccine (flu shot) protects against the three types of influenza viruses that are most likely to cause the flu that year. The flu shot cannot give you the flu. When there is a good match between the influenza strains in the vaccine and the influenza strains circulating in the community, the vaccine can prevent influenza illness in about 60% to 80% of healthy children and about 80% of healthy adults. Protection may last for one year. The flu shot does not protect against colds or other illnesses with flu-like symptoms.
When should I get the flu shot?
As the flu shot takes two weeks to provide full protection, the earlier you get the vaccine the better. The flu shot is available starting October 25 2012. Clinics run until January 2013.
I got a flu shot last year. Do I have to get it again this year?
Yes. You should get the flu shot each fall. The viruses that cause the flu change frequently. Protection from last year's vaccine has likely worn off. You need to get another shot to be protected this year.
Who should get the influenza vaccine?
Everyone who is six months of age or older should get the flu shot, unless there is a medical reason that prevents you from getting the vaccine (see Who should not get the flu shot?). If you are at high risk for flu-related complications (see Who is at risk?) or live or work with people who are at high risk (e.g. healthcare workers and essential community services staff), getting the flu shot is very important.
How many doses of the vaccine do I need?
Adults should receive one shot each year. Children between six months and eight years of age who never had a seasonal flu shot should receive two doses the first year they get vaccinated, one month apart. Children who have had a dose of the flu vaccine in the past only need one shot this season.
What are the side effects of the flu shot?
The flu shot is very safe and cannot cause influenza. The most common side effects are soreness or redness where the shot is given. Children can get a fever. Side effects usually occur one to two days after vaccination.
Severe side effects and allergic reactions are rare. Oculorespiratory syndrome (ORS) causing red eyes, swelling of the face, coughing, wheezing and difficult breathing rarely occurs. In very rare instances (about one in one million doses of vaccine), the flu shot has been associated with a temporary neurological condition causing muscle paralysis called Guillain-Barré Syndrome (GBS). Seek medical attention if you believe that you, or someone in your care, had a reaction to the shot.
Who should not get the flu shot?
- People with a severe allergy to any component of the vaccine (e.g., neomycin, kanamycin, thimerosal)
- People who have had a serious allergic reaction to a previous dose of influenza vaccine
- Babies younger than six months of age
- Any person who had Guillain-Barré Syndrome (GBS) or who has an active neurological disorder should speak with a doctor before getting vaccinated.
- People who have a severe allergy to eggs should speak to their doctor about safely getting the vaccine in a two step graded dosing
- Most people who have had Oculorespiratory syndrome (ORS) can safely receive the vaccine but should speak to their doctor first.
- Anyone who is ill with a fever should delay receiving the flu shot until they feel better
What should I do if I get the flu?
Get plenty of rest and drink lots of fluids. Wash your hands often. Stay at home and away from people until you are feeling better. Your doctor can advise you about medication to reduce aches, pain and fever or may prescribe anti-influenza drugs to ease your discomfort and shorten the length of your illness. Children should not be given medication that contains acetylsalicylic acid (e.g. aspirin) because it can cause Reye's Syndrome, a sickness that can lead to brain and liver damage.
Where can I find more information?
Talk to your doctor or call Toronto Public Health at 416-338-7600.
Last updated October 2012