The World Health Organization estimates that every year more than two million deaths are prevented worldwide due to immunization.
Vaccines have saved more lives in Canada than any other medical intervention in the past 50 years. Before vaccines became available many Canadians died from diseases such as diphtheria, measles and polio that are now preventable by immunization. Vaccines make it possible for British Columbians to live free of the illness and disability associated with many vaccine-preventable diseases.
Immunization has been so successful that many of the diseases vaccines prevent are now rare in Canada. However, the viruses and bacteria that cause vaccine-preventable diseases still exist. If we stop immunizing (or if immunization rates drop), these diseases will come back. Before long we would see epidemics of diseases that are nearly under control today.We have seen this happen in other countries. For example:
Immunization helps keep these diseases under control — for good.
It’s just like… a boat that has a slow leak - with the water being the disease, and a bucket for bailing being the vaccine. Before we started vaccinating, the boat was filled with water. As more people became immunized, we started bailing water out of the boat. In modern times you could say that we have been bailing fast and hard, and now the boat is almost dry. We could say, "Good. The boat is dry now, so we can throw away the bucket and relax" — except that the leak hasn't stopped. Before long, we'd notice water seeping in, and soon it might be back up to the same level as when we started.
While immunization has reduced many of the diseases we vaccinate against to very low levels in Canada, some of these diseases are still quite common in other parts of the world. Because of international travel all it takes is plane ride for diseases like polio, diphtheria and measles to arrive in our communities. Without immunizations these diseases could spread quickly.
An example: In 2014, the Fraser Valley experienced a measles outbreak of over 400 cases. The outbreak was linked to a family returning from a trip overseas where a child was infected with measles. Low immunization rates in the community allowed measles to spread quickly.
Vaccines are one of the most monitored and studied things in medicine because they are given to healthy children and adults.
Vaccines are approved for use in Canada only if they meet very strict standards for safety and effectiveness. The majority of vaccine side effects are mild and last for only a day or two. Serious side effects following vaccination, such as a severe allergic reaction, are very rare. It is much safer to get the vaccine than to get the disease. Visit our vaccine safety page to learn more.
Vaccines have spared millions of people the effects of devastating diseases. This graphic from the Public Health Agency of Canada shows how effective vaccines have been at reducing disease in Canada:
Immunizations don't just protect the people getting immunized, they protect everyone around them too.
When most people in a community have received a vaccine for a particular disease, the chance of that disease spreading within the community is greatly reduced. That’s because it will have nowhere to go – if a sick person comes in contact only with people who are immune (have been vaccinated), the disease will have little opportunity to spread. This indirectly protects infants who are too young to be vaccinated, people who cannot be vaccinated for medical reasons (e.g., certain immunocompromised people) and people who may not adequately respond to immunization (e.g., the elderly). This type of protection is called herd immunity. But when fewer people in a community are immunized, it is easier for a disease to spread from person to person and cause an outbreak.
Watch this short video to learn more about how herd immunity works:
Video source: Video courtesy of Health Canada. All contents may not be reproduced without permission and are copyright of Her Majesty the Queen in Right of Canada, Represented by the Minister of Health, 2012.
If you are a health care provider looking for immunization information, please visit the Health Professionals section of the BCCDC website. There you can find clinical resources, immunization courses, print resources for patients and more.
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