The Power of Vaccines

Published Thursday, August 4, 2022

The Power of Vaccines

By Lily Colquhoun, Prevention and Screening Clinical Services

Vaccines are one of the most important developments in the history of global health. In fact, vaccines have been saving lives around the world for more than 200 years. Until the 1900s, most deaths were due to infectious diseases. As health care systems developed, penicillin was discovered and more vaccines were made available, chronic diseases replaced infectious diseases as a leading cause of death.

Due to widespread vaccine use, many infectious diseases such as pneumococcal disease, measles, and diphtheria are not common, and others like smallpox and polio were completely eliminated in developed countries. While modern health care has made leaps and bounds in treating other infectious diseases, it is still important for us to engage in preventive healthy behaviours to avoid getting sick.

No matter how healthy we are, it is still possible to get very sick, or even die, from infectious diseases. The good news is that getting vaccinated makes our bodies stronger and more resistant to disease. It protects our health and the health of those around us by helping the community develop population immunity.

Population immunity (also known as community immunity or herd immunity) occurs when a large percentage of people are immune to a specific disease either from prior infection or from vaccination, and a disease is no longer able to spread easily to others. While prior infection can help to reach population immunity, vaccination can create immunity without causing illness. Achieving population immunity this way is also important because it protects those with compromised immune systems and those who may not be able to get vaccinated. This includes our most vulnerable people, like very young children and people who are sick or aging.

Some vaccines contain weakened or inactive parts of a particular organism, called an antigen, that triggers an immune response within our bodies. Other vaccines contain the blueprint (mRNA) for antigens instead of the organism itself. Vaccines will not cause the disease in the person receiving the injection, but instead cause a response in the body similar to how it would react if it encountered the actual organism. Essentially, vaccines teach our bodies how to fight off illnesses so that if we do encounter them, our bodies already know how to defend against them.

Vaccines are not the only thing keeping us healthy, but they play a large role. Research continues to advance vaccine development and bring us closer to a world free from infectious disease. It is important for us to stay up to date with our vaccines, not just to protect ourselves, but to protect others too. Are you up to date? Find out by visiting


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