How vaccines are tested
Did you know?
Vaccines are among the most strictly regulated medical products in Canada. All vaccines go through an in-depth testing process and must be shown to be safe and effective before being approved for use in Canada.
- Vaccine safety.
- The immune response to the vaccine.
- Vaccine efficacy (how well the vaccine prevents the disease.)
Vaccine safety monitoring
Once a vaccine has been approved for use, its safety is continuously monitored. Ongoing vaccine safety monitoring is essential for the detection of and quick response to vaccine safety concerns.
The purpose of ongoing post-marketing vaccine safety monitoring is to detect possible adverse events that:
- Occur at a higher frequency level than expected based on clinical trials or historical experience.
- Occur very rarely, too rarely to detect even in a large clinical trial. When millions of people receive a vaccine, rare side effects may be recognized.
What is an adverse event?
How vaccine safety is monitored in Canada
Vaccine safety is also monitored at the international level. The World Health Organization’s International Drug Monitoring Program collects reports from over 75 countries (including Canada). It uses this global data set to monitor for any vaccine safety concerns.