Yoopya with The Conversation
As the fall months settle in, Canadians are being urged to take precautions against the upcoming flu season.
Flu season in Canada typically peaks between December and February, but the virus can circulate much earlier. Public health officials are advocating for early vaccination, emphasizing that the annual flu vaccine is the most effective way to protect against infection and reduce the severity of illness.
Clinics across Canada offer flu shots free of charge.
Influenza
Influenza, commonly known as the flu, is a respiratory illness caused by influenza viruses that spread easily from person to person. These viruses mainly affect the nose, throat and lungs. Flu symptoms typically include fever, chills, muscle aches, cough, congestion, runny nose, headaches and fatigue.
Unlike the common cold, which often develops slowly, the flu tends to hit suddenly and can lead to severe complications like pneumonia, bronchitis and even death, particularly in high-risk groups such as young children, seniors over 65, pregnant individuals, and those with chronic conditions like asthma, diabetes or heart disease.
Influenza spreads mainly through droplets when an infected person coughs, sneezes or talks. These droplets can land in the mouths or noses of people nearby, or they can linger on surfaces where the virus can survive for up to 48 hours. Preventive measures such as handwashing, mask-wearing and staying home when symptomatic help reduce the spread of the virus.
How the flu vaccine works
Each year, flu vaccines are updated to protect against the influenza viruses that research indicates will be most common during the upcoming season. The flu shot contains inactivated or weakened influenza viruses, which cannot cause the flu but help the immune system develop antibodies. These antibodies protect against infection when exposed to live flu viruses.
The vaccine typically takes about two weeks after administration for immunity to build up, which is why public health officials recommend getting vaccinated in the fall, before flu rates start to rise. This gives individuals enough time to develop immunity before influenza becomes more widespread.
Can you get flu and COVID-19 vaccines together?
Public health experts have confirmed that it is safe to receive the flu vaccine and the COVID-19 vaccine at the same time. Doing so can provide protection against both illnesses and reduce the chances of severe complications from either virus. Administering both vaccines during the same visit is a convenient way to ensure you’re protected for the season, especially as COVID-19 continues to circulate alongside influenza.
Benefits of the flu shot
One of the key benefits of flu vaccination is that it significantly reduces the risk of severe illness, hospitalization and death from the flu. While flu vaccines aren’t 100 per cent effective at preventing infection, they greatly lessen the severity of the illness and reduce the spread of the virus in the community. This is especially important for protecting high-risk groups like seniors, children, pregnant people and individuals with chronic health conditions.
Additionally, widespread flu vaccination helps prevent the health-care system from becoming overwhelmed, especially in a year when other respiratory viruses like respiratory syncytial virus (RSV) and COVID-19 are still circulating. By reducing the overall number of flu-related hospitalizations, vaccines also free up health-care resources for other urgent needs.
Why get vaccinated every year?
One of the unique challenges of influenza is that the virus mutates constantly. Because of these frequent changes, immunity from last year’s vaccine won’t provide full protection this season. This is why the flu vaccine is updated annually to match the most prevalent strains of the virus.
Even if a person received a flu shot the previous year, it’s important to get vaccinated again to stay protected against new viral strains circulating in the population. Flu vaccines are reformulated each year based on global surveillance data collected by organizations like the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC).
Misconceptions about the flu vaccine
Despite clear benefits, misconceptions about the flu shot continue to contribute to low vaccination rates.
Some people believe that the flu vaccine can cause the flu, but this is a myth. The inactivated viruses in the flu vaccine cannot cause illness. After receiving the vaccine, some people may experience mild side-effects like soreness at the injection site or a low-grade fever, but these symptoms are short-lived and far less severe than a full-blown flu infection.
Another misconception is that the flu shot is not necessary for healthy adults. While healthy people may have a lower risk of severe flu complications, they can still spread the virus to more vulnerable individuals, such as young children, seniors or immunocompromised family members. Getting vaccinated helps protect both the individual and the community through herd immunity.
Author:
Jennifer Guthrie | Assistant Professor of Microbiology and Immunology, Western University