Seunga (Jasmine) Han, PharmD Student
It’s that time of the year again – flu season. Come October and November, at least in Canada and you’ll likely see signs and posts everywhere, in pharmacies and doctor’s offices, telling you to get your flu shot. Among many vaccines, the flu shot is the one that receives the most scrutiny from the public, and many are skeptical of its efficacy and safety. Today, we’ll cover various topics on influenza and influenza vaccines in the hopes of answering some of the questions you may have had before getting your flu shot.
What is influenza?1
Influenza, also know as “the flu,” is a respiratory infection caused primarily by the influenza A and B viruses. In Canada, influenza generally occurs every year in the late fall and winter months, which is why we start getting vaccinated around October and November.
Some signs and symptoms of the flu include sudden onset of high fever, cough, muscle aches, headache, chills, loss of appetite, fatigue, sore throat, nausea, vomiting, and diarrhea. While many recover from the flu in about 7-10 days, some may be at risk of other complications like pneumonia.
Is influenza contagious?1,2
Yes! The influenza virus is extremely contagious and can be transmitted from person-to-person through tiny droplets that are spread when a person coughs, sneezes or even talks. People infected with the virus are contagious as early as 1 day before and for up to 5 to 7 days after they actually feel sick.
How can I prevent influenza?2
Because influenza is spread through droplets (e.g. coughing and sneezing) as well as both direct and indirect contact, some of the best ways to prevent influenza are:
- Getting immunized: It’s the best way to prevent influenza.
- Covering your mouth when sneezing or coughing: its best to cover yourself with your arm, but not with your hands.
- Proper hand hygiene: You could use hand sanitizers as well, but keep in mind that washing your hands is more effective.
- Stay home when you feel sick
Who decides on what’s in the annual flu vaccine?1
Specifically, in Canada, annual influenza vaccines (what we call “the flu shot”) are made according to recommendations developed by the Influenza Working Group. They look into various factors to make the most appropriate recommendation such as who should get vaccinated, how serious the influenza is, the safety and efficacy of the vaccines, among many others.
Why do I need to get the flu shot each year?1,2
This is probably one of the most commonly asked questions by many. The annual flu shot is recommended every year as its the most effective way to prevent influenza and it’s complications, which are ranked among the top 10 leading causes of death in Canada. Unlike with other viruses, the flu-virus mutates every year at approximately the same time. Therefore, researchers are constantly re-identifying the most infective strains every year, and therefore vaccinating, again and again, is always necessary.
Who should get it?1,2
In Canada, influenza vaccination is recommended for anyone who is 6 months and older, especially those at high risk of influenza-related complications or hospitalization, including:
- All pregnant women
- People with underlying health conditions
- Residents of nursing homes and other chronic care facilities
- People 65 years of age and older
- Children under 60 months of age
- Indigenous Peoples
Since influenza vaccines are not as effective in infants less than six months of age, the flu shot is not recommended under normal circumstances.
Who should NOT get it?1
If any of the following applies to you, it’s important that you talk to your healthcare provider as you should not be receiving flu shots.:
- You’ve previously developed an anaphylactic reaction to a previous influenza vaccine dose or to any of the vaccine components
- You have a history of Guillain-Barré Syndrome (GBS) within six weeks of influenza vaccination
However, if you have an allergic reaction to eggs, you CAN be vaccinated against influenza without having done a vaccine skin test. Egg allergies are no longer considered a risk factor for receiving a shot, ask your healthcare provider if you have any concerns.
Is it safe?1,2
All influenza vaccines in Canada are considered safe and well-tolerated. It’s safe even in those with latex allergies. Some individuals may experience redness, tenderness, warmth, fever, fatigue, headache or body aches. So, it’s important to stick around for 15 minutes after receiving your injection whether it’s at a pharmacy or a clinic for safety measures and in case of anaphylaxis (serious allergic reaction).
Does the flu shot actually work?
How well the vaccine works changes from year to year. For example, in 2017/18, it was estimated that the overall effectiveness of influenza vaccines was about 36%, whereas the 2016/17 and 2015/16 were 40% and 48%, respectively. Why do the success rates vary? The Influenza Working Group can only do so much to predict which strains will be infectious every year. Therefore the vaccine is never truly perfect.
Regardless of the reported effectiveness, the influenza vaccine reduces the risk of getting influenza by about half, but it also helps to reduce the severity of the flu if you were to get it. Not only that but becoming immunized also stops the spread of influenza to those around you, which is crucial for the populations that can’t vaccinate, such as those below six months of age, seniors and pregnant women. Since the shot’s protection usually kicks-in about two weeks after you receive your shot, it’s best to get it as soon as possible.
Where can I get the influenza vaccine?
Depending on where you live, you may be able to speak to your community pharmacist, family physician, public health centre or primary care provider to get vaccinated.
We hope you took away something valuable from this piece. If you have any questions or concerns regarding this article or others, feel free to reach out to us on Instagram, Facebook, or at email@example.com with your feedback. We’d love to hear from you.
- Public Health Agency of Canada. (2018, March 06). Canadian Immunization Guide Chapter on Influenza and Statement on Seasonal Influenza Vaccine for 2017–2018. Retrieved September 1, 2018, from https://www.canada.ca/en/public-health/services/publications/healthy-living/canadian-immunization-guide-statement-seasonal-influenza-vaccine-2017-2018.html#new
- Alberta Health Services. (n.d.). Influenza Immunization. Retrieved September 1, 2018, from https://www.albertahealthservices.ca/influenza/influenza.aspx
- Centers for Disease Control and Prevention. (2018, February 15). Seasonal Influenza Vaccine Effectiveness, 2005-2018. Retrieved September 2, 2018, from https://www.cdc.gov/flu/professionals/vaccination/effectiveness-studies.htm