with Dr. Martin Lavoie
Why is it recommended to get vaccinated against influenza and now against COVID-19 every fall?
Each year, many respiratory viruses circulate and spread in our communities. The respiratory virus season is most active during the fall and winter months, typically spanning from October to March. Its exact timing, duration, and the impact on our health and wellbeing vary from year to year, but it happens every year and we see significant disease, complications, and death every year. A few viruses are better known and more impactful like influenza (some people call it « the flu » but that is a confusing term for many – influenza is a respiratory virus, not a gastro-intestinal one), COVID-19, and RSV.
The reason we recommend receiving certain vaccines every year is because the protection we get from those particular vaccines does not last forever, and particularly because many viruses evolve and change over time (looking similar like siblings at first but becoming more like cousins and distant cousins over time), so our immune system needs to get updated instructions to keep current with our protection against those viruses. This is particularly true for influenza and COVID-19.
What are vaccines? Why do they work so well?
To reduce the risk of disease and suffering, we have a variety of vaccines we can use to protect ourselves (direct protection) and others around us (by reducing the risk of spread – indirect protection).
Vaccines are manufactured products that contain ingredients able to safely and successfully guide our immune system to recognize and attack things that can cause us to be sick, like bacteria and viruses. Vaccines are very good at giving our immune system the knowledge to quickly recognize and respond to viruses in advance of being in contact with them. Your body safely learns and gets trained to defend itself because the vaccine does not cause the disease but provides enough details of the virus or bacteria for the immune system to get to work right away.
We can choose to get our immune system trained by getting the infection or by getting vaccinated.
The fall and winter infections are not so bad, are they? Do we really need vaccines?
There is more out there than the common cold, sniffles, and sneezes during the fall and winter months. There are viruses like influenza, COVID-19, and RSV that have caused and continue to cause significant disease and suffering, including death, each year. In fact, influenza causes around 3500 deaths each year in Canada. We don’t have vaccines to protect against everything that circulates, but we are fortunate to have the influenza and COVID-19 vaccines to protect us.
There is also a long list of other infections and conditions for which we have been able to develop excellent and safe vaccines. Vaccines have made a HUGE difference in our lives over the last many decades. In fact, they are so good at protecting us that most people forget how bad some infections were or can be, or even what some of those look like. For example, infants and young children used to be hospitalized and sometimes die following infections such as measles, diphtheria, meningitis, tetanus, and poliomyelitis. Many of those infections were leading to severe complications and long-term after-effects, such as deafness, brain damage, sterility, or paralysis.
We eradicated smallpox from the world back in 1980, ending very severe disease and stopping its death toll. We have essentially eliminated measles from most parts of the world, and we only rarely see it nowadays. Similarly, many other infections were significantly reduced in numbers and severity thanks to vaccines.
If we made many infections disappear or, for the most part, got them under control, why do we keep using those vaccines?
What we see today is the result of decades of efforts to reduce the presence of many viruses and bacteria, but it is also a direct result of where our current immunity barrier is at the individual and community level. We only rarely see measles, for example, only because we have a lot of immunity in our communities (i.e., very high immunization rates) so that even when a few cases come into Canada from other countries, the measles virus is not able to find people who are vulnerable to it because they have very long-lasting learned immunity from the vaccine they received as children to protect them from being infected.
Without maintaining that immunity barrier in our communities, one case of measles would spread like wildfire, causing the return of large outbreaks, which would lead to severe cases and infant and childhood deaths. Until we can eradicate the cause of an infection, like we did for smallpox, those viruses and bacteria continue to be present, and our immunity defence needs to be maintained.
Are there any new or less-used vaccines that could make a difference?
One excellent vaccine that has now been available for about six years in Canada is the vaccine that protects against shingles. While not widely available via funded programs, it is a safe vaccine that offers excellent protection from shingles, a condition that can be debilitating due to the intensity of the pain it can cause, and that can lead to long term nerve pain. This vaccine is recommended for individuals who are 50 years of age or older.
Another vaccine to keep an eye on is the RSV vaccine. Until recently, we did not have a vaccine to protect against RSV; that being said, we have a product made of antibodies offered to infants at high risk of severe RSV disease. Earlier this year, a vaccine that should help protect elderly individuals was approved for use in Canada. This vaccine has yet to be reviewed by the National Advisory Committee on Immunization, which will assess its safety and capacity to protect individuals from RSV infection and severe disease.
One last thing: make sure you get your information on infections and vaccines from trusted and reputable sources. There is a lot of information out there, and it can be misleading, incorrect, biased or completely made up. Some of that can be unintentional, but we know that it can also be wilfully posted to mislead and cause harm.
Dr. Martin Lavoie is a physician with a specialty in public health and is a Clinical Instructor at the School of Population and Public Health in the Faculty of Medicine at the University of British Columbia. A graduate of Université de Montréal in 1996, he has practised public health/community medicine in Québec, Alberta, and British Columbia.