Influenza (commonly known as "the flu") is a serious, acute respiratory illness that is caused by a virus. People who get influenza may have a fever, chills, cough, runny eyes, stuffy nose, sore throat, headache, muscle aches, extreme weakness and fatigue. Note: the elderly may not have a fever. Children can also have earaches, nausea, vomiting, and diarrhea. The cough and fatigue can persist for several weeks, making the return to full personal and work activities difficult.

People of any age can get the flu. Illness due to influenza usually lasts two to seven days; sometimes longer in the elderly and in people with chronic diseases. Most people who get influenza are ill for only a few days. However, some people can become very ill, possibly developing complications and requiring hospitalization.

Influenza spreads by respiratory droplets in infected persons through coughing, sneezing or talking. It is also spread through direct contact with surfaces contaminated by the influenza virus, such as toys, eating utensils, and unwashed hands.

When there is a good match between the vaccine influenza strains and circulating influenza strains, the vaccine is about 70 to 90 per cent effective in preventing influenza infection in healthy adults. In children, it is about 77 to 91 per cent effective against influenza respiratory infection. In elderly people, the vaccine can prevent pneumonia and hospitalization in about 60 per cent, and prevent death in about 80 per cent.

Protection from the vaccine develops by about two weeks after receiving it, and may last up to one year. People who receive the vaccine can still get influenza, but if they do, it is usually milder. However, the vaccine will not protect against colds and other respiratory illnesses that may be mistaken for influenza.

No. The vaccine does not contain live virus so you cannot get the flu from the vaccine.

It is best to receive the influenza vaccine in October to mid-November before the flu season starts. This will give your body time to build protection against the influenza virus. It takes about two weeks after the vaccination to develop protection against influenza.

Because the influenza virus changes often, it is necessary to get the flu shot every year, for protection against the virus strains that may be circulating that year.

Children younger than nine years of age, being vaccinated for flu for the first time, need two doses given at least one month apart. The second dose of influenza vaccine is not needed if the child has received one or more doses of vaccine during a previous influenza season.

No. For the 2005/2006 season, the influenza vaccine is available free of charge to individuals aged 6 months or older who live, work or attend school in Ontario. The vaccine will be available from physicians and through community-based flu clinics offered by public health units, Community Health Centres (CHCs), Community Care Access Centres (CCACs), public hospitals, Long-Term Care Homes (LTCHs), pharmacies as well as employer-sponsored clinics.

After you receive your vaccination, ensure that the doctor or nurse updates your personal immunization record. Keep it in a safe place!

Healthy people should get vaccinated to protect themselves and their families from influenza and to avoid missing quality time (including holidays) with their families, to avoid losing time from work, and to avoid spreading the virus to others.

Influenza is much worse than a cold. Even healthy, young people can become quite ill. You might bring the influenza virus home to a baby, older relative, or someone with a medical condition who could develop serious complications from influenza.

Children can also benefit from influenza vaccination. Influenza in preschoolers is associated with acute middle ear infections. Influenza may also lead to hospitalization in healthy children (particularly those under two years of age) as well as in children with underlying high-risk medical conditions. Children are also the main spreaders of the virus, in both the school and household settings. Influenza vaccination can help to decrease the incidence of middle ear infections associated with influenza, reduce school absenteeism and help to prevent community transmission of influenza.

The influenza vaccine, like any medicine, is capable of causing side effects, which can be either mild or, in few cases, severe. The risk of the vaccine causing serious harm is extremely small. Almost all people who get the flu vaccine have no serious problems.

Most people who get the vaccine have either no side effects or mild side effects such as soreness, redness or swelling at the injection site. Life-threatening allergic reactions are very rare. If they do occur, it is within a few minutes to a few hours after the vaccine.

Guillain-Barré Syndrome (or GBS)
GBS is a very uncommon disease that causes muscle paralysis and has been associated with certain infectious diseases. Overall, the risk of GBS occurring in association with vaccination is small. In comparison to the small risk of GBS, the risk of illness and death associated with influenza is much greater.

Oculo-Respiratory Syndrome (or ORS)
During the 2000/2001 season, a small number of people who received the vaccine developed a generally mild side effect called Oculo-Respiratory Syndrome or ORS. The 2001 case definition of ORS is: the onset of bilateral red eyes and/or respiratory symptoms (cough, wheeze, chest tightness, difficulty breathing, difficulty swallowing, hoarseness or sore throat) and/or facial swelling occurring within 24 hours of influenza vaccination.

All individuals who have experienced ORS symptoms in the past may be safely re-immunized with influenza vaccine except those who have experienced ORS with severe lower respiratory symptoms (wheeze, chest tightness, difficulty breathing) within 24 hours of influenza vaccination. These individuals should seek expert medical advice before reimmunization.

You should seek medical attention if you believe you or someone in your care has had a reaction to a vaccine. The following are serious adverse vaccine events:

a) Persistent crying or screaming, anaphylaxis (hives, swelling of the mouth and throat, throat constriction, difficulty swallowing or breathing), wheezing, chest tightness, paleness, weakness, dizziness or fast heart beats or anaphylactic shock occurring within 48 hours after the administration of influenza vaccine.

b) Shock-like collapse, high fever or convulsions occurring within three days after the administration of influenza vaccine.

c) Arthritis occurring within 42 days after the administration of influenza vaccine.

d) Generalized hives (urticaria), residual seizure disorder, brain disease (encephalopathy), inflammation of the brain (encephalitis) or any other significant occurrence* occurring within 15 days after the administration of influenza vaccine.

OR

e) Death occurring at any time and following upon a symptom described in clause (a), (b), (c) or (d).

Note: * Significant occurrences which are unexpected or unusual in severity including reactions such as Oculo-Respiratory Syndrome (ORS) and Guillain-Barré Syndrome (GBS).

All of the above should be reported to your health care provider who will report these occurrences to your local public health unit.

Recommended recipients of the flu vaccine:

Persons at risk for influenza-related complications:

1. Healthy children aged 6-23 months.
2. People 65 years of age or over.
3. Adults and children with chronic cardiac or pulmonary disorders (including bronchopulmonary dysplasia, cystic fibrosis, and asthma) severe enough to require regular medical follow-up or hospital care.
4. Adults and children who have any condition that can compromise respiratory function or the handling of respiratory secretions or that can increase the risk of aspiration.
5. People of any age who are residents of nursing homes or other chronic care facilities.
6. Adults and children with chronic conditions such as diabetes mellitus and other metabolic diseases, cancer, immunodeficiency, immunosuppression (due to underlying disease and/or therapy), renal disease, anemia and hemoglobinopathy.
7. Children and adolescents (aged 6 months to 18 years) with conditions treated for long periods with acetylsalicylic acid.
8. People at high risk of influenza complications (as outline as above) embarking on travel to destinations where influenza is likely to be circulating.

Persons capable of transmitting influenza to those at high risk for influenza-related complications:

1. Health care providers who work in facilities and community settings, such as physicians, nurses and emergency response workers.
2. Health care and other service providers who have contact with residents of continuing care facilities or residences.
3. Those who provide home care for persons in high-risk groups.
4. Those who provide services within closed or relatively closed settings to persons at high risk (e.g. crew on ships).
5. Household contacts (adults and children) of people at high risk of influenza complications. This includes household contacts of: 1) children < 6 months of age, who are at high risk of complications from influenza but for whom there is no currently licensed vaccine, and 2) children aged 6 to 23 months whether or not they have been immunized. Pregnant women in their third trimester should be vaccinated if they are expected to deliver during influenza season, as they will become household contacts of their newborn.
6. Those providing regular child care to children aged 0 to 23 months, whether in or out of the home.
7. People who provide essential community services.
8. People in direct contact with poultry infected with avian influenza during culling operations.

General Population:

Individuals aged 2 to 64 should be encouraged to receive the vaccine even if they are not in one of the above mentioned priority groups.

The following persons should not get the influenza vaccine:

• Infants under six months of age (the current vaccine is not recommended for this age group).
• Anyone with a serious allergy (anaphylaxis) to eggs or egg products. A serious allergic reaction usually means that the person develops hives, swelling of the mouth and throat or has trouble breathing after eating eggs or egg products.
• Anyone who has a severe allergy to any component of the vaccine. (Please see product monographs.)
• Anyone who had a serious allergic reaction to a previous dose of the influenza vaccine.

Also:

• Anyone who has developed GBS within 6 to 8 weeks of a previous influenza vaccination.
• Anyone who is acutely ill with a fever should usually wait until the fever goes down before being vaccinated.
• Vaccination should be delayed in individuals with active neurologic disorders, but should be considered when the disease process has been stabilized. (Please see product monographs.)
• Anyone with an acute respiratory infection or any other active infection (please see Fluviral® product monograph.)

If you are looking for general information about influenza or the vaccine, the province's Universal Influenza Immunization Program or the location of a clinic near you, please call: 1-877-844-1944 (TTY#1-800-387-5559) or visit this website.

If you have questions about the vaccine that are specific to your medical condition, you should ask your doctor or call your local public health unit.

August 2005

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