Pharmacovigilance: Committing to safety for Canadians – The case of COVID-19 vaccine

By Victoria Bugaj, Jacob Poirier, and Certina Ho

We can all agree that the year 2020 can be summarized with one word: unprecedented. The same velocity with which COVID-19 swept throughout the world, medical experts and pharmaceutical industry scientists worked diligently to provide a solution. There has never been more interest, expertise, or upfront investment dedicated to providing the world with a vaccine. In less than one year from the onset of the global pandemic, Canada approved the first COVID-19 vaccine for use in December 2020.

Pharmacovigilance: Committing to safety for Canadians

In today’s society where it can be difficult to identify and verify credible sources of information, it is not surprising that the public perception on the safety of a new drug or a new vaccine may be divided. What everyone may not be fully aware of, however, are the rigorous systems that are in place to ensure the safety of Canadians before and after a drug product or a vaccine is approved.

The Clinical Trials Database is managed by Health Canada. It provides a public listing and source of information related to phase I, II and III clinical trials in patients involving human pharmaceutical and biological drug products:

  • Phase I clinical trials are usually performed on healthy volunteers to find out the pharmacological actions of and the safety (i.e. side effects) associated with increasing doses of the drug.
  • Phase II clinical trials are meant to assess the efficacy of the drug in patients with medical conditions to be treated/diagnosed/prevented, and to find out the safety (i.e. side effects) and risks associated with the drug.
  • Phase III clinical trials are intended to collect additional information to confirm the clinical efficacy and safety under the proposed conditions of use for the drug. In other words, these trials evaluate the drug’s efficacy, safety, and effectiveness (i.e. how well it works) in people.

The evaluation of safety and efficacy of a drug product or a vaccine does not stop when the product is approved; in fact, once a drug or a vaccine becomes available in the market, it is constantly being monitored and evaluated for safety. In addition to phase I, II and III clinical trials, what may be lesser known is Phase IV clinical trials:

  • Phase IV clinical trials are studies performed within the approved indication after the drug has been approved. This is part of post-market surveillance and reflects the combined effort of the pharmaceutical industry and Health Canada to continuously survey for adverse reactions related to the drug or the vaccine once it is approved. This process ensures every approved drug product or vaccine is continuously monitored for rare adverse events that may not have been captured in previous phases of clinical trials.

The COVID-19 vaccine

Although, the COVID-19 vaccine was developed and approved in less than a year, one must keep in mind that the abundance of resources available for this to occur was unparalleled. As a result, the multiple phases of clinical trials took place simultaneously with Health Canada’s review of the incoming data and evidence.

Drug manufacturers are obligated to relay any reported adverse events to Health Canada by performing risk monitoring activities, post-marketing studies and encouraged expedited reporting of possible adverse events associated with their products. For example, as with all drug products, the COVID-19 vaccines are subject to Good Pharmacovigilance Practices (GVP) Guidelines. According to the guidelines, the manufacturer is required to report serious adverse drug reactions (with respect to the drug) to Health Canada within 15 days after receiving or becoming aware of the information. Mandatory reporting of serious adverse drug reactions and medical device incidents by hospitals to Health Canada is also effective as of December 16, 2019. In addition, under the Health Canada’s Canada Vigilance Program, an online portal is available where anyone can report a side effect to a drug, a vaccine, or a health product. When combining reports from all sources, it allows for the opportunity to identify and highlight potential safety concerns, including those that may have been previously unrecognized.


Although the speed at which the COVID-19 vaccines entered the market has been unprecedented, rest assured the safety and reporting standards to which they are upheld are no different than any other drug products or vaccines. In fact, in response to the pandemic, Health Canada made a commitment to increase the monitoring and assessment of any vaccine safety issues via amplified collaboration and data sharing between global health partners, including the World Health Organization. This diligent monitoring of adverse reactions is an ongoing process, which ultimately helps to ensure safe administration of the COVID-19 vaccine for all Canadians. For further information, please refer to the “Vaccines and treatments for COVID-19: Safety after authorization” website at



Victoria Bugaj and Jacob Poirier are PharmD Students at the Leslie Dan Faculty of Pharmacy, University of Toronto; and Certina Ho is an Assistant Professor at the Department of Psychiatry and Leslie Dan Faculty of Pharmacy, University of Toronto.