A Blast into the Past
As of May 30, 2020, three major organizations led the race to a vaccine for the SARS-CoV-2 virus: Moderna, Pfizer, and Oxford University. Both the Moderna and Pfizer vaccine adopted messenger RNA(mRNA) technology, which is relatively new in the vaccine world. Oxford University’s ChAdOx1 nCoV-19 vaccine was slightly different; it compared viral strains from COVID-19 to infectious diseases from the past, such as the Middle East Respiratory Syndrome (MERS) and the Severe Acute Respiratory Syndrome (SARS).
On July 27th, the Moderna vaccine, mRNA-1273, was approved for Phase 3 study in collaboration with the NIH and BARDA. Oxford University’s ChAdOx1 nCoV-19 also entered its third and final stage of development in July. Meanwhile, Pfizer’s BNT162 Vaccine had progressed into a combined 1 and 2 testing stage.
Number of various phases of vaccine development (New York Times).
What makes Pfizer's BNT162b2 vaccine successful?
Pfizer, an American-based pharmaceutical company, took over the news last month upon announcing its BNT162b2 vaccine's success. Pfizer claimed that mRNA vaccines are more flexible and take less time to produce than inactivated vaccines. mRNA vaccines are especially effective since one can gain immunity to more than one version of the virus upon the expression of a protein found on all or most versions of the virus. This is especially important for a virus with which the world is still not entirely familiar, such as SARS-CoV-19.
Understanding the vaccine (BBC News).
Pfizer reported a 95% efficacy rate from its Phase 3 study of the vaccine, involving over 43,000 participants.
After receiving Pfizer’s submission on October 9th, 2020, Health Canada authorized its vaccine on December 9th, 2020, under the Interim Order Respecting the Importation, Sale and Advertising of Drugs for Use in Relation to COVID-19. It's important to note that as of December 20th, the vaccine has only been approved for people of 16 years of age or older since its effectiveness on younger ages is not yet established. Currently, the Pfizer-BioNTech virologists are running trials to include possibly include children of younger age groups in the future.
Administrating the Pfizer Vaccine
The vaccine is inserted into the muscle of the arm by a 0.3 mL injection and is best efficient when taken in two doses: an initial dose followed by a second dose 21 days later. The study also concluded that people might not gain immunity against COVID-19 until at least seven days after the final dose.
The individual getting the vaccine might face the same side effects after the BNT162b2 vaccine as any other vaccine: pain at the sight of the injection insertion, body chills or feeling tired or feverish.
Where Canada Stands
Approximately 200,000 doses of the Pfizer vaccine Canada has ordered will arrive next week. In March, four million of the 20 million doses secured by Canada of the Pfizer vaccine is expected to arrive.
Canada could also order up to 168,000 doses of the Moderna vaccine by the end of December if it is approved. Previously, Canada announced that it is estimating approximately two million of the 40 million doses of the Moderna vaccine to arrive in Canada by the end of March 2021. Health Canada is still waiting on data regarding Moderna’s manufacturing plants, which is expected to arrive by next week, before approving Moderna’s vaccine entirely.
Moderna also requires two doses of its vaccine to immunize the subject to COVID-19, similar to the Pfizer vaccine; its second dose is projected to be given 28 days after the initial dose.
Canada is hopeful about supplying the Moderna doses to Indigenous communities or Northern Territories, where it may be challenging to store the Pfizer vaccine, which requires exceptionally cool conditions.
Back in September 2020, Dimitris Polygenis, President of McKesson Canada Pharmaceutical Solutions and Specialty Health, one of the largest distributors of pharmaceutical drugs in Canada, published a report: “Is Canada’s Supply Chain Ready for a COVID-19 Vaccine?”. One of the company's biggest concerns is concerning the storage and transport conditions for the vaccine frontrunners. Both vaccines must be stored in extremely cold temperatures, and current infrastructures were not built for these conditions. Additionally, the COVID-19 vaccines might coincide with flu shot distribution.
Canadians to Receive the Vaccine First
Seniors and healthcare workers are some of the first demographics to be receiving the vaccine. Vaccine distribution is not very easy to predict as a lot of it depends on the need for vaccines. For example, as high-density regions witness more cases, they might be prioritized during the vaccine delivery process after citizens of high-risk age groups receive their dosage.
Some of the first recipients to receive the vaccine (Toronto Star).
After the Vaccine
The pandemic won’t completely be over as soon as the vaccine arrives. “A vaccine will not be perfect, and it takes time for the immune system to be ready to protect us”, said Julian Daniel Sunday Willet, a Ph.D. student at McGill University.
The long-term immune response of both vaccines is still unknown. Whether the Pfizer or Moderna vaccine can prevent the person from transmitting the virus or not is still unknown. People must take the same precautions even after vaccines roll out: social distancing, wearing masks, gathering in smaller numbers, and more. Masks will be mandatory even after the population is vaccinated.
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Article Author: Palak Agarwal
Article Editor: Olivia Ye