Influenza Immunization


The flu is a commonly used term to describe Influenza. It is a highly contagious respiratory disease caused by a virus. Symptoms may include fever, head / body aches and pains, weakness, sneezing, sore throat, cough and sniffles. People with the flu are usually bedridden for up to a week or more.
Some people confuse "the flu" with having a cold or having "the stomach flu"(vomiting and/or diarrhea). Although there are many other viruses that may cause those symptoms, Influenza is a virus that manifests itself as a respiratory disease. Influenza is spread easily through coughing, sneezing or through touching contaminated surfaces or objects like unwashed hands, toys, eating utensils, door knobs etc.
The real dangers of the flu are the complications that may arise from the disease such as:

  • Risk of other infections, like pneumonia
  • Risk of heart or kidney failure
  • Risk of nervous system disorders

**Immunization is the most effective way to prevent Influenza and its complications particularly for those people in the high risk groups. **
The Ontario Ministry of Health and Public Health Branch recommends the flu vaccine (as well as the pneumococcal vaccine) to specific groups of people. Please ask your doctor or nurse for further information.

Who should get the influenza vaccine?
High Risk Individuals

  1. Adults and children with chronic heart or lung disease e.g. asthma.
  2. People of any age who are residents of nursing homes and other chronic care facilities.
  3. People over 65 years of age and older.
  4. Adults and children with chronic conditions such as diabetes, metabolic diseases, cancer, poor or depressed immune systems, kidney disease, or blood disorders.
  5. People with conditions that compromise the management of respiratory secretions and are associated with an increase risk of aspiration.
  6. Children and adolescents between 6 months to 18 years of age who have been treated with aspirin for a long time.
  7. Health Care and other personnel who have contact with people in the high risk categories.
  8. Household contacts, including children (older than 6 months of age), who have contact with people in the high risk categories.
  9. People who provide essential community services e.g. firemen, policemen.
  10. High risk individuals who are traveling to areas where influenza may be circulating. Travelers should check with a travel clinic or their local public health unit several weeks before traveling.

Immunization of healthy persons is encouraged even if they are not in one of the high risk categories.

* People capable of transmitting influenza to those at high risk of influenza-related complications:

  • Health Care and other care providers in facilities and community settings who through their activities are potentially capable of transmitting influenza to those at high risk of Influenza complications
  • Household contacts (adults and children) of people at high risk of influenza complications, whether or not they have been immunized. These persons include household contacts of children< 6 months of age (who are at high risk of complications from Influenza but for whom there is no available effective vaccine) and of children aged 6 to 23 months. Pregnant women should be immunized in their thirst trimester if they are expected to deliver during the flu season, as they will become household contacts of their newborn.
  • Those providing regular child care to children aged 0 to 23 months, whether in or out of the home
  • Those who provide services within closed or relatively closed settings to persons at high risk (e.g. crew on ships).
  • People who provide essential community services.
  • People in direct contact with avian-influenza infected poultry during culling operations.
  • Health persons aged 2 to 64 years, who should be encouraged to receive the vaccine, even if they are not in one of the aforementioned priority groups.

* Canada Communicable Disease Report (CCDR), 15 June, 2006
The best way to protect yourself, your family and patients is to have the flu shot every year.

 How well does the vaccine protect against the flu??
The vaccine is about 70-90% effective in preventing influenza illness in healthy adults. The vaccine is less effective in high risk individuals, so those who live with them (older than 6 months of age) should be vaccinated.
The vaccine takes about two weeks to develop antibodies against the viruses so getting the vaccine early is important. The antibodies may last up to six months in healthy people and four months in others.
In elderly people, the vaccine can prevent hospitalization for pneumonia in about six out of ten people. Some people who receive the vaccine may still get the flu, however the symptoms are usually less severe than those who did not receive the vaccine.

What are the potential side effects?
The vaccine generally causes mild side effects that occur infrequently. Most people who receive the vaccine either have mild reactions or none at all. The most common effect may be a sore or tender arm at the injection site, or rarely fever, lethargy, or muscle aches. These effects may last 24 to 48 hours. In persons who are not allergic, acetaminophen may be taken to help prevent these mild side effects. Other side effects can include redness of the eyes with or without discharge and cough.
Although serious allergic reactions can occur, they are very rare. If they do occur, it is within a few minutes to a few hours after receiving the injection.

Who should not have the vaccine?
People who have

  • had a severe reaction to a flu shot taken in the past.
  • Infants under six months of age.
  • a known sensitivity or allergy to any component of the vaccine. Components may include thimerosal, neomycin, pork gelatin and deoxycholate.
  • a serious allergy (anaphylaxis) to eggs or egg products.
  • an active / changing neurological (nervous system) condition.
  • a history of Guillan-Barre Syndrome.
  • an acute illness or fever.

The best defense in preventing influenza is getting the flu vaccine every year and by practicing good hand washing.  Another important way to prevent the spread of germs that make you and others sick is to “Cover your Cough”, and clean your hands after coughing or sneezing, using soap and water, or an alcohol based hand cleaner.

Where can you get the influenza vaccine?
You can get it from your family physician, walk in clinics, Region of Peel Health community clinics and through your workplace occupational health clinics.
If you have any questions about whether you should get the Flu vaccine and where to get it, talk to your Doctor, Nurse, Local Public Health Department, Hospital Infection Prevention and Control Department, or Hospital Occupational Health & Safety Department.

You may also access the following websites for additional information:

Authors: Lina S. Di Carlo, RN, COHN (C), Manager, Occupational Health & Safety
Anne Archibald RN, COHN (C), Occupational Health and Safety
Updated: February 2007

Credit Valley Hospital