About Vaccines

Immunization saves lives! Consider this: 100 years ago, infectious diseases were the leading cause of death worldwide. In Canada, they now cause less than 5% of all deaths - thanks to immunization. Today, diseases such as polio and diphtheria occur very rarely in North America, largely because we have been vaccinating against them for a long time.

It is important that individuals stay up-to-date and follow Ontario's immunization schedule. Vaccines help protect against illness and outbreaks in communities.

What are vaccines and immunization?

A vaccine is a substance that primes the body's immune system to make antibodies, T-cells and memory cells, which are the body's defense against infection. When you are vaccinated you build up your immune system, making you stronger and more resistant to disease as you grow. Vaccines are the best way to protect you and your family against some very serious infections. The National Advisory Committee on Immunization (NACI) and the Canadian Pediatric Society strongly recommend routine immunization.

Like eating well and exercising, getting vaccinated is a foundation for a healthy life. Immunizations save lives by preventing serious illnesses, and are recognized as one of the greatest successes in modern medicine.

When an individual is vaccinated, their bodies make antibodies that fight specific infections. If they are not immunized and come in contact with one of these infections, they may get very sick and potentially experience complications, or even die.

In Ontario, publicly funded vaccines are given to protect against the following diseases: rotavirus, diphtheria, pertussis (whooping cough), tetanus, polio, haemophilus influenzae type b (Hib), measles, mumps, rubella (German measles) hepatitis, influenza, chickenpox, meningococcal disease, pneumococcal disease and human papillomavirus (HPV).

There are also a number of vaccines for other circumstances, for example, people traveling to a country with diseases that are not common in Canada, such as typhoid fever. Travel vaccines are currently not publicly funded in Ontario. For more information, speak to your health care provider.

Safety and effectiveness

All vaccines have to be tested to make sure they are both safe and effective. The most common side effects are mild pain, swelling and redness where the injection was given.

Some infant vaccines may cause a low-grade fever (approximately 38°C) or fussiness for a day or two after the injection. Physicians may recommend acetaminophen to prevent fever and pain. Serious side effects from immunizations are rare. Please report any side effects or severe vaccine reactions to your health care provider or local public health unit. You should always discuss the benefits and risks of any vaccine with your health care provider.

Vaccines are very effective in preventing disease when given as recommended. However, no vaccine will work for 100 per cent of individuals who receive it. Studies of disease outbreaks show that although some immunized children or youth can develop the infection, the illness is often less severe.

Read more about Safety and Effectiveness in the Myths and Facts section.

Fact sheets on publicly funded vaccines in Ontario

For More Information

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