COVID-19: How vaccines are developed 

With described video



The following animated video uses colorful illustrations to represent people and things.

An animation of the coronavirus appears on screen. A series of dots demonstrate how the virus can spread.  

Four vaccines enter the frame from the corners of the screen and limit the spread of the virus.

Narration: Vaccines are the most effective way to prevent the spread of infectious disease, but developing one can be costly, long, and complex.

Dots form the outline of a map of the world which then transforms into the image of a syringe used to administer a vaccine.

Narration: However, with significant investment and collaboration at a global scale, developing a vaccine is possible in a much shorter period of time.

Narration: So how are vaccines developed today? And will the development of a COVID-19 vaccine be different?

Illustrations of a microscope, a mouse and a person appear in sequence to demonstrate the three stages of vaccine development.

Narration: All vaccines go through three basic stages of development:  the exploratory stage, the pre-clinical stage, and the clinical stage.

Two scientists are working in a lab with a microscope, beakers and vaccines.

Narration: In the exploratory stage, scientists do basic laboratory research to find vaccines that could help us develop immunity to a disease before being exposed to it.

The date, January 11, 2020, appears at the top of the screen. A DNA helix twirls across the screen. Planet earth appears rotating above the DNA helix.

Narration: On January 11, 2020, the genetic code of the virus causing COVID-19 was published. This allowed scientists all over the world to start working on finding potential vaccines.

Human cells appear across the top of the screen. Five syringes inject vaccines into the human cells.

Narration: With more than 150 in development worldwide, scientists are using current approaches, like using whole or parts of killed or weakened virus, and newer techniques aimed at delivering the virus's DNA directly into cells.

A mouse is seen in a laboratory setting. The vaccine is tested on the mouse and a check mark shows it was successful.

Narration: In the pre-clinical stage, scientists use laboratory and animal studies to identify safety concerns before testing the vaccine in humans. It is also used to help find the safest dose.

A man rolls into the frame revealing his left arm. He is injected with the vaccine and a checkmark appears showing that the vaccine was successful.

Narration: While many vaccine candidates don't progress beyond this point, successful ones move on to the clinical stage where they are first tested in humans.

A chart shows the number of participants increasing as the vaccine goes through each of the three phases.

Narration: This stage normally consists of 3 phases.     

Four animated people representing different genders and ethnicities appear on screen. A check mark appears above each one.

Narration: Phase 1 trials usually involve a small number of healthy volunteers to test safety and confirm that the vaccine causes an immune response.

The outline of a person appears on screen surrounded by a shield that repels the coronavirus.

Narration: An immune response simply refers to how our bodies recognizes and defends itself from viruses and other potentially harmful substances.

Rows of people appear on screen then fade away.

Narration: Promising vaccines then progress to Phase 2, where they are given to hundreds of participants, including groups at risk of the disease. The goal of Phase 2 is to test the vaccine's safety at the proposed doses and method of delivery, and again, to assess the immune response.

Narration: Phase 3 studies involve thousands of volunteer participants and compare groups that received the vaccine to those that didn't.

A coronavirus in a circle appears in the middle of the frame.

The coronavirus in a circle disappears to reveal a shield with a checkmark in the middle. The shield zooms out of the frame.

Narration: These studies are used to further answer whether the vaccine works and still demonstrates that it is safe for use.

Two scientists appear on screen.

Narration: One way scientists have worked to reduce the time to develop a COVID-19 vaccine, has been to use study designs that allow merging of clinical phases.

An illustration shows people from Phase 2 merging with participants in Phase 3.

Narration: For example, new approaches have allowed for Phase 2 participants to be included in larger Phase 3 studies, allowing scientists to shorten the overall timeline and number of participants needed, without cutting corners or compromising safety.

Narration: The first COVID-19 vaccine trials in humans started in March of 2020. Since then, tens of thousands of volunteers have been enrolled in clinical studies worldwide.     

An illustration shows Health Canada scientists reviewing the results of clinical studies and giving their approval.

Narration: Health Canada, responsible for regulating the use of vaccines in Canada, has authorized clinical trials for COVID-19 vaccines. Before approving a new vaccine, they look closely at all of the data on it, paying very close attention to its safety.

A series of vaccines are marked with a red X to show they have been rejected until one is approved.

Narration: Many vaccines will fail somewhere along this path if they don't work or are unsafe – it's normal and this is the purpose of all of the stages of development and clinical trials. Only those that are proven safe, effective, and of high quality will be approved for use in Canada.

A street with stores, people walking on the sidewalks, and cars on the street fades in and then out.

Narration: A safe and effective vaccine will bring us one step closer to the widespread and long-term management of COVID-19.

A COVID-19 vaccine vial with a syringe appears along the bottom of the frame, with a maple leaf inside a shield.

Narration: Visit to learn more.

The Canada wordmark fades on screen.

The music ends. The screen goes black.

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