Now that the Oxford-AstraZeneca vaccine has been approved for use in Canada, three different jabs are on the menu for Canadians hoping to protect themselves against the coronavirus.
However, while all the vaccines have the same goal — to inoculate the recipient against COVID-19 — the vaccines are by no means identical.
And while Canada’s contracts secure enough doses from the three manufacturers to vaccinate everyone in the country by September, not everyone will be getting the same kind of jab.
Global News has broken down the key details of the three vaccines to help you understand which dose is going into your arm.
What kinds of COVID-19 vaccines are available?
- Pfizer: mRNA
- Moderna: mRNA
- AstraZeneca: adenovirus-based
All of these vaccines use fairly new vaccine technologies, but they don’t all use the same kind.
Pfizer and Moderna’s vaccines use mRNA technology, which delivers genetic instructions for our cells to make viral proteins themselves. The body then begins to train itself to fight these proteins, building its immunity to the same protein found in COVID-19.
The Oxford-AstraZeneca vaccine works differently. It was built using a kind of virus called an adenovirus, which causes colds in chimpanzees. These adenovirus-based vaccines represent a newly approved method of vaccination that has been studied for decades. The adenovirus is altered to carry a gene for the coronavirus protein, which can then train a person’s immune system to recognize the actual coronavirus if it ever enters the body.
How effective are the COVID-19 vaccines?
- Pfizer: 95 per cent
- Moderna: 94.1 per cent
- AstraZeneca: 62 per cent
Each of the vaccines has been found to be effective in combatting the coronavirus. However, they don’t all offer the same amount of protection.
Pfizer and Moderna have a photo-finish for first place in terms of effectiveness. Clinical trials found Pfizer’s vaccine was 95 per cent effective, while Moderna’s vaccine nipped at Pfizer’s heels with an effectiveness of 94.1 per cent.
The distant bronze goes to the Oxford-AstraZeneca vaccine, which was found to be 62 per cent effective in a two-dose clinical trial.
However, researchers accidentally gave a sub-group of participants a half-dose on their first jab of the Oxford-AstraZeneca jab, followed up by a full second dose. This group saw a leap in the vaccine’s ability to shield them from the virus, with the outcome proving to be 90 per cent effective.
Because this was just a sub-group within the clinical trial, the vaccine was only approved for use in its full, two-dose iteration — which is over 30 per cent less effective than Pfizer and Moderna’s vaccines.
Still, at the end of the day, Canadians should feel confident that any one of the three approved vaccines will cut off COVID-19’s claws and protect them from the worst outcomes of the virus.
“If there is a vaccine and it’s been authorized by Health Canada, it means that it’s met standards,” said Dr. Supriya Sharma, chief medical advisor with the regulatory branch of Health Canada, said on Friday.
- Posters promoting ‘Steal From Loblaws Day’ are circulating. How did we get here?
- Canadian food banks are on the brink: ‘This is not a sustainable situation’
- Video shows Ontario police sharing Trudeau’s location with protester, investigation launched
- Solar eclipse eye damage: More than 160 cases reported in Ontario, Quebec
She explained that in clinical trials, all the vaccines were found to quash the worst outcomes in coronavirus patients.
“The number of cases of people that died from COVID-19 that got vaccine was zero. The number of people that were hospitalized because their COVID-19 disease was so severe was zero. The number of people that died because of an adverse event or an effect of the vaccine was zero,” Sharma said.
“So in the areas where we’re really looking to prevent serious illness, prevent hospitalizations and of course prevent death, all of these vaccines are good.”
How are the COVID-19 vaccines stored?
- Pfizer: -70°C
- Moderna: -25°C to -15°C
- AstraZeneca: 2°C to 8°C
Just like people, some of these vaccines are pickier than others about the temperature they like to hang around in.
Of the three vaccines, Pfizer is the most particular — and it likes things chilly. This vaccine requires ultra-cold storage, meaning it has to be transported and stored at -70 C. This makes the vaccine tricky to ship to remote regions, where the appropriate infrastructure is far more difficult to set up.
Enter the Moderna vaccine, which is a little less discerning. While this vaccine still likes the cold, it isn’t quite as particular as the Pfizer jab. The Moderna doses can be stored in a freezer between -25 C and -15 C. That’s why the territories have been guaranteed priority access to this particular vaccine, as it’s much easier to safely transport and store.
This category is also where AstraZeneca’s vaccine truly shines. The doses can be stored at normal fridge temperature — meaning the doses are much easier to both ship and keep.
How many doses of each COVID-19 vaccine are required?
- Pfizer: two
- Moderna: two
- AstraZeneca: two
Pfizer, Moderna and AstraZeneca’s vaccines are all two-dose shots — leaving little room for relief for those Canadians who get sweaty palms at the very thought of needles.
Some, including the head of Ontario’s vaccine rollout Gen. Rick Hillier, have pushed for Moderna to be approved as a single-dose vaccine, as the jab has proven to be about 80 per cent effective after the first injection.
However, no clinical trials have been conducted to prove whether that inoculation lasts long-term — and Moderna hasn’t shown any interest in conducting further trials to determine if less effective, one-time vaccine is a safe and effective option.
Who can take the COVID-19 vaccine?
- Pfizer: 16+
- Moderna: 18+
- AstraZeneca: 18+
While Canada is on track to have tens of millions of doses available to Canadians this year, not everyone who may want the vaccine will be able to take it.
Pfizer’s clinical trials were only conducted on those over the age of 16, which means that until further studies are completed in younger age groups, anyone under 16 years old is ineligible for the jab. The same issue comes into play for both Moderna and AstraZeneca, which only conducted their clinical trials on Canadians over the age of 18.
Moderna is currently conducting additional studies in children over 12 years old, so teens may be able to access the jabs once that work is done.
However, age isn’t the only limitation those hoping to be vaccinated may face. Anyone who is allergic to the ingredients in the vaccines is not allowed to receive the injections, and pregnant or breastfeeding mothers have been asked to consult their doctors before moving ahead with their vaccinations.
Finally, if you have COVID-19, you can’t get the vaccine until you’re better.
How many doses is Canada getting?
- Pfizer: 40 million doses
- Moderna: 40 million doses
- AstraZeneca: 20 million doses
Out of the three approved vaccines, individual Canadians are most likely to wind up receiving the Moderna vaccine. Canada’s agreement with Moderna is for 40 million doses — although the feds have the option of purchasing another 16 million in addition to that. The 40 million doses are enough to inoculate 20 million Canadians, over half of the population.
Meanwhile, Canada has 40 million Pfizer doses secured in its agreement with the manufacturer. That’s enough to inoculate another 20 million Canadians, which means that between Pfizer and Moderna alone, Canada has enough doses to vaccine every Canadian and then some.
As for the agreement with AstraZeneca, Canada has purchased 20 million doses — enough to vaccine another 10 million Canadians. That means that between the three agreements, Canada has enough doses to inoculate 40 million people, which is more than the entire population, within the year.
Should Canada opt to purchase more of any of the vaccines, there’s no guarantee they’d arrive any faster than the initial 80 million doses. Any additional doses would be entirely dependent on the manufacturer’s production capacity, which is under serious strain as every country battles to get the vaccines.
Either way, Canada’s current vaccine agreements point in an optimistic direction: every Canadian who wants a vaccine should be able to access one in 2021.
Comments