flu vaccine
Starting Oct. 17, UHN staff, students and volunteers will be able to receive a flu vaccine at all UHN sites. (Photo: Flickr, NIH)​

It's that time of year again! UHN's flu shot campaign starts on Monday, Oct. 17.

Based on our success over the last two years, UHN is continuing the "shot-for-shot" initiative with UNICEF. Every flu shot received by a UHN staff member, student or volunteer means a child in need receives a tetanus, polio or measles vaccine. There will also be a contest that rewards one person from each UHN site with a gift card. Stay tuned for more details to come!

In the meantime, be sure to read the FAQ on influenza and the vaccine that can protect you, your family, your co-workers, and our patients from this infectious disease.

What is influenza?

Influenza is a serious contagious viral respiratory infection.

Symptoms can range from mild to severe. Typically, influenza starts with a headache, chills and cough. This is followed by fever, muscle aches, fatigue, loss of appetite, runny nose, sneezing, watery eyes, throat irritation, and in children, sometimes diarrhea and vomiting. Most people recover from influenza within a week to 10 days.

The influenza season usually lasts from October to April, but the exact time can change every year. Typically the peak time for influenza is end of December to mid-January.

What about other respiratory viruses?

Multiple viruses can cause illness that may be very similar or look identical to influenza. These viruses include respiratory syncytial virus (RSV), human metapneumovirus and others. They tend to circulate in the community at the same time as influenza. In fact, most illnesses that look like influenza during flu season are actually caused by viruses other than influenza.

A research study from 2014​ found that during the peak of influenza, other respiratory viruses contribute substantially to adult respiratory hospitalizations and mortality, and actually exceed the influenza in elderly patient populations.

Is Influenza serious?

Influenza is one of the top 10 infectious diseases in Ontario. While most healthy adults feel miserable for a few days, for some people, influenza can be serious or life-threatening.

Those most at risk include:

  • Adults age 65 and over
  • People who are immunocompromised
  • Pregnant women
  • Children under the age of five
  • People who are obese
  • People with chronic medical conditions, including asthma, heart disease, and diabetes, among others.
  • Residents of long-term care facilities


It is estimated​ that, in a given year, an average of 12,200 hospitalizations related to influenza and approximately 3,500 deaths attributable to influenza occur in Canada.

Complications include pneumonia, bronchitis, and sinus and ear infections. Influenza and other respiratory virus infections can also make chronic conditions, such as asthma, worse.

How are these viruses spread?

Influenza and other respiratory viruses are spread by droplets that are made when infected people cough or sneeze. You can either catch the virus directly from an infected person or by touching surfaces contaminated with the virus.

You are most likely to spread the virus when you have symptoms.

How do I avoid getting influenza and other respiratory viruses?

Getting vaccinated against influenza will provide some protection against you getting influenza. Given that the vaccine isn't perfect and that multiple other viruses can cause similar illness, it is important that we don't just rely on the flu shot for protection.

There are several other important infection control measures that can help you avoid getting ill with or spreading a respiratory infection.

  • Wash or sanitize your hands frequently 
  • Cough and sneeze into a tissue or your sleeve, not your hands
  • If you are sick with symptoms of the flu or any respiratory virus, you should not be at work, even if you had the flu shot this year
  • In the rare chance that you have to be at work while ill, you must avoid patient contact and wear a surgical mask when you are around others. Try to go home as soon as you can
  • If you can, avoid close contact with individuals who have symptoms that are suggestive of influenza-like illness. If you can't avoid close contact with individuals who have such symptoms, wear the appropriate Personal Protective Equipment (PPE) when caring for them

Limiting the spread of respiratory viruses is everyone's responsibility.

Do I have to get vaccinated?

We strongly encourage you to get the influenza vaccine, but at this time the influenza vaccination is not mandatory for health-care workers at UHN. It's not that we think influenza vaccination isn't important, we think it's incredibly important and would like to see all of our staff lining up at the flu carts this year.

We also acknowledge, however, that the flu shot isn't perfect and this is why we need you to take other measures as well to protect yourself and our patients from respiratory viruses, including influenza.

There is, however, one setting where influenza vaccination is required.  If you are working on a unit where an influenza outbreak has been declared, it is required that you be vaccinated and/or take prophylactic medication until the outbreak is over.

Employees who are not vaccinated and refuse the prophylactic medication may be placed on an unpaid leave of absence (LOA) until the outbreak is over. If an employee is placed on an unpaid LOA they may use banked lieu time or vacation credits. If an employee is not able to receive the vaccine for medical reasons and a medical certificate is provided, the employee will be reassigned where possible during the outbreak. This is recognized in the ONA collective agreement. 

I got vaccinated last year. Why do I need to get it again?  

Different influenza viruses circulate every year. Even if there is no significant change in the virus, your body's immunity level declines over several months.  Also, immunity from the influenza vaccine decreases over time. It's best to get the vaccine every year to keep yourself healthy.

How effective is the influenza vaccine?

The effectiveness of the seasonal influenza vaccine varies from year to year. Some years the vaccine is more effective than others because it's a closer match to what's circulating in the community.

Overall, decades of experience suggest that the influenza vaccine is, on average, 60 per cent effective in preventing infection in healthy adults.  Evidence also shows that even if a person gets influenza after being vaccinated, their illness will be less severe. Although the vaccine is not perfect, getting immunized is one of the best ways available to prevent influenza infection.

Remember that influenza vaccine can only prevent influenza, not influenza-like respiratory illness that may be caused by other viruses. 

I heard that getting vaccinated year after year may cause the vaccine to be less effective in future years. Is that true?

Some new research suggests that, in certain years, having been vaccinated before can make the vaccine a bit less effective in the current year.  The medical community is currently investigating this intermittent phenomenon but as it stands now, annual vaccination is still recommended and likely will continue to be recommended.

Can you get influenza from the vaccine?

No, you can't get influenza from the vaccine because the viruses contained in the vaccine are inactivated (killed) and cannot cause influenza. 

You can still catch the other respiratory viruses that are circulating at the same time as influenza.  Also, if you have been exposed to influenza right before vaccination (i.e., before your body has built immunity to the virus from vaccination), you may get sick from that infection and mistakenly attribute it to the vaccine.

What is UHN's approach to influenza season this year?

As many of you know, recently a number of our peer hospitals implemented a policy of mandatory vaccination or masking throughout the flu season. UHN has not implemented this policy. We instead continue our policy of supporting vaccination and most importantly, imploring our staff not to come to work when ill with influenza-like illness.

We hope that with an honest approach to vaccination and information on general well-being, as well as an improved process, we can boost our vaccination rates to over 60 per cent range.

What should I do if I also work at a hospital that isn't part of UHN?

If you work at other hospitals you need to find out what their policy is this year and follow that while you work there.

I'm allergic to eggs. Can I get the vaccine?

Yes, most people with an egg allergy can get the influenza vaccine. If you are able to eat baked goods with eggs then you are able to get the vaccine. If you have a severe egg allergy (anaphylaxis), you need to speak to your doctor. You may be able to get the vaccine in a medical clinic or in your allergist's office.

I'm pregnant. Can I still take the vaccine?

In most cases, not only is it safe, it is recommended that pregnant women get vaccinated. Some studies suggest that pregnant women are at greater risk of developing complications from influenza.

Pregnant women who get vaccinated also pass on their immunity to their baby, protecting them from influenza for the first six months of their life.

What is Guillain-Barré Syndrome (GBS) and how do you get it?

GBS is a rare neurological disorder. Many years ago, there was a batch of influenza vaccine that scientists thought was associated with an increased risk of GBS. Since then, there has been no evidence to suggest the influenza vaccine leads to GBS.

In fact, recent research suggests you actually have a higher risk of developing GBS from getting influenza than from getting the vaccine.

What is UHN doing about visitors who are sick when they come here?

We are tightening up our visitor policy to reflect the same expectations of visitors that we have of staff.

Is there anything new that we should be aware of for this year's flu campaign?

In addition to offering a "shot for a shot" in support of vaccination of children in developing countries, this year's influenza vaccine campaign will provide one gift card per site for receiving the flu vaccine. Stay tuned for more details!

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