What you need to know about the first doses of COVID-19 vaccine in Canada at the start of deployment


Health Canada says the side effects from Pfizer’s clinical trials were found to be “mild or moderate” and included things like pain at the injection site, body chills, and feeling tired and feverish.

A COVID-19 vaccine from Pfizer has arrived in Ontario and Quebec, with the first inoculations scheduled for Monday morning in Toronto, Montreal and Quebec.
Canada is expected to receive 249,000 doses of the drug from the US pharmaceutical giant and its German partner BioNTech by the end of the month and four million total doses – enough to immunize two million people – by March.

Here’s what we know about today’s vaccinations and the Pfizer product:


Five frontline workers will be the first Ontarians to receive the vaccine on Monday at one of Toronto’s hospitals.

Ontario received 6,000 doses over the weekend and plans to vaccinate about 2,500 more healthcare workers. Each person vaccinated needs two doses, 21 days apart.

In Quebec, residents of long-term care homes in Montreal and Quebec will be the first to receive vaccines, followed by staff.


Pfizer developed its vaccine with a novel technique of using messenger RNA (mRNA), which essentially teaches our cells how to make the coronavirus spike protein and trigger an immune response if we become infected with the virus to it. to come up.

Pfizer’s vaccine uses a synthetically produced mRNA that is packaged in a fatty or lipid coating. When injected into the muscle of the upper arm, the lipid attaches itself to the cells and discharges mRNA into them. It is then translated into protein to make the antibody.

Another prominent vaccine candidate from Moderna also uses mRNA. One from AstraZeneca uses a non-replicating viral vector – a virus that has been stripped of its genetic material and replaced with the gene for the coronavirus spike protein. This viral vector produces an mRNA molecule, and from there, protein and antibodies.


Pfizer’s vaccine is 95% effective in preventing SARS-CoV-2 infection from one week after the second dose, and Health Canada says on its website that people may not be protected against the COVID-19 before at least seven days after the second dose.

The rate of effectiveness is based on studies involving approximately 44,000 participants.

What is not known is the duration of immunity with one of the main vaccine candidates.


Health Canada says side effects from Pfizer’s clinical trials were found to be “mild or moderate” and included things like injection site pain, body chills, and feeling tired and feverish.

The organization says these are common side effects of many vaccines and “do not pose any health risk.”

“As with all vaccines, there is a chance that there is a serious side effect, but these are rare,” the website says. “A serious side effect could be something like an allergic reaction. ”


Pfizer’s vaccine, like Moderna’s and AstraZeneca’s, requires two doses injected about three weeks apart.

Follow-up will become especially important with a two-dose vaccine, to ensure that people return to their doctor or pharmacy to receive their second dose, and to ensure that they receive the correct vaccine if more than one option. is available.

Storage could also be problematic with the Pfizer product, which requires ultra-low freezers that can keep it at minus 70 C until a short time before injection. Moderna needs a temperature of around minus 20 ° C – about the same as a regular freezer.

Pfizer and Moderna need cooler temperatures for their vaccines due to mRNA instability. AstraZeneca vaccine, on the other hand, can be stored in the refrigerator.

This report by The Canadian Press was first published on December 14, 2020.

The canadian press


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