Chances are good that you will be exposed to influenza at some point this season. While the flu vaccine isn’t perfect, it remains your best protection against illness.

How effective is the flu vaccine?

The flu vaccine causes antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with the viruses that are in the vaccine.

How well the flu vaccine works to prevent you and your loved ones from getting ill can range widely from year to year. The vaccine’s effectiveness can also vary depending on:

  • The person being vaccinated (such as their age and health). In general, the flu vaccine works best among healthy adults and older children.
  • The similarity or “match” between the flu viruses expected to be circulating this season and the ones selected for the flu vaccine this year.
Dr. Simon Kapaj, Deputy Medical Health Officer, Saskatoon Health Region.

Dr. Simon Kapaj, Deputy Medical Health Officer, Saskatoon Health Region, receives his flu shot.

The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. During years when the flu vaccine is well matched to circulating viruses, the vaccine can reduce the risk of flu illness by about 50 to 65 per cent among the overall population.

During years when the flu vaccine is not well matched to circulating viruses, the benefits drop. But remember that the flu vaccine protects against three to four different strains of influenza. Last year’s vaccine provided very good protection against the H1N1 strain and the B viruses. In addition, antibodies you develop when vaccinated against one flu virus can sometimes provide protection against different but related viruses. This year’s vaccine is expected to be a closer match for the H3N2 strain still circulating from last year.

How effective is the flu vaccine in the elderly?

Older people with weaker immune systems often have a lower protective immune response after flu vaccination compared to younger, healthier people. So, the vaccine is less effective for this group.

 If the vaccine works less well in older people should they still get vaccinated?

Although the flu vaccine is not perfect, there are plenty of good reasons why those 65 and older should be vaccinated each year.

First, this age group is at high risk of getting seriously ill, being hospitalized and dying from the flu.

Second, some protection is better than no protection at all. Think about the use of seat belts. They may not fully protect us in the event of a major high-speed crash; however, most of us would welcome whatever extra protection they afford. Likewise, even though the flu vaccine may not prevent infection, illness may be milder after being immunized.

Third, the flu vaccine lowers the risk of death and hospitalization. Hospitalizations in the frail elderly can mark the beginning of a major decline in overall health and mobility. It can also trigger a host of complications that result in no longer being able to live independently.

What are the benefits of flu vaccination for other groups?

While the effectiveness of the flu vaccine can vary, there are a lot of reasons to be immunized each year.

  • Flu vaccination continues to offer the best protection against influenza infection.
  • If you do get infected with influenza, you’re likely to be less sick if you have been vaccinated.
  • When more people get vaccinated against the flu, less flu can spread through our community. Flu vaccination can help protect people around you who may be at greater risk of getting seriously ill or dying from influenza, such as older adults, people with chronic health conditions and young children (especially infants younger than six months old who are too young to get vaccinated).
  • Flu vaccination helps protect women during pregnancy and their babies for up to six months after they are born.
  • Flu vaccination can reduce the risk of more serious flu outcomes, such as hospitalization for all age groups.
  • The flu vaccine is safe, effective and free.

Where can I get a flu vaccine?

Flu vaccines are offered in many locations, including doctor’s offices, public health clinics, pharmacies, and by some employers. For more information on public health flu clinics, visit

Arm yourself – get the free vaccine today!

Submitted by Population and Public Health