How Vaccines are Developed and Approved for Use in Canada
March 27, 2026
Written By Hanna Dada, Health Resource Navigator
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Vaccines are the most effective way to prevent the spread of infectious diseases. The development process is rigors and with investment and collaboration globally can be much quicker than in the past without impacting safety.
All vaccines go through three basic stages of development: the exploratory stage, the pre-clinical stage, and the clinical stage.
Exploratory: Scientists develop a potential vaccine.
Preclinical: Scientists conduct lab and animal studies before testing on humans.
Clinical Trials: Vaccines are complex biological products. There are strict evidence requirements that need to be met before they can be authorized for use in healthy people. Large clinical trials are required to demonstrate a vaccine’s safety and effectiveness.
We have 3 phases of clinical trials:
Phase I: 10s of volunteers
- Is the vaccine safe?
- What is a safe dose?
- Are there any side effects?
Phase II: 100s of volunteers
- How well does the vaccine work?
- Is it safe for a larger number of people?
- What is the safest and most effective dose?
Phase III: 1000s of volunteers
- Does the vaccine prevent disease?
- What are the side effects?
Then, the manufacturer submits an application to Health Canada for review and approval.
The steps for Review and Approval of Vaccines:
Scientific Review: Teams of Health Canada experts conduct a thorough and independent review of all vaccine data.
Approval: Health Canada approves a vaccine if it is safe, it works, it meets manufacturing standards, and the benefits outweigh the risks.
After, the government start distribution, vaccination and monitoring
Distribution: Governments coordinate the purchase, logistics and distribution of vaccines across Canada.
Vaccination: All Canadians have access to the vaccine.
Ongoing Monitoring and Review: Continuous monitoring and review to confirm the safety of the vaccine and that benefits outweigh risks.