Health Topics

Vaccine Safety

Vaccines must be safe because they are given to healthy people to prevent disease. Vaccines undergo rigorous testing before they are approved for use. The side effects of the vaccine must be minimal for it to be approved for use. Vaccines are continuously monitored for safety. The risks of the diseases vaccines prevent are much greater than any risk of the vaccine.

The Biologics and Genetic Therapies Directorate of Canada is responsible for determining the safety and efficacy of vaccines. They review all clinical information on vaccines, including trials, safety data and efficacy. They do not approve vaccines for use until the quality and safety is sufficient.

Vaccine approval

Here are the steps vaccines go through for approval.

Before approval of vaccines:

  1. Canadian researchers working in universities, research institutes, government organizations, industry and clinical settings research diseases and vaccines.
  2. Health Canada’s Biologics and Genetic Therapies Directorate supervises vaccine production and tests early vaccine batches in the lab.  They test vaccines in a lab to ensure the vaccine produces the proper immune response and will not be toxic to humans.
  3. Pharmaceutical companies complete three phases of clinical trials.

After approval of vaccines:

  1. The National Advisory Committee on Immunization recommends how to use the vaccine.
  2. The Canadian Paediatric Society’s Infectious Diseases and Immunization Committee gives advice for childhood vaccine programs.

After release of vaccines:

  1. Health Canada’s Biologics and Genetic Therapies Directorate tests selected vaccine lots.
  2. Post-license clinical trials test long-term vaccine effectiveness.
  3. The Public Health Agency of Canada tracks adverse events through the Canadian Adverse Events Following Immunizations Surveillance System to ensure the continued safety of a vaccine. It also allows identification of very rare adverse events that may not show up in clinical trials.

Adverse events

An adverse event is any health problem that occurs after vaccination. The event may or may not be related to the vaccine. Adverse events could include a sore or red arm or even death from a car accident. If any adverse event occurs within 30 days following the vaccination, it is included in final safety data. At the end of testing, adverse events are reviewed to determine whether they may or may not be caused by the vaccine.