Promising vaccines on the horizon, but more data needed
Health Canada right to wait, experts say
OTTAWA • Canada’s vaccine rollout could be faster with two promising vaccines still under regulatory scrutiny, but experts agree health Canada shouldn’t rush the process simply to satisfy public demand.
The country’s rollout currently depends on vaccines from Pfizer and Moderna, both of which are in short supply as companies ramp up production. Pfizer complicated the situation further this week, drastically cutting Canada’s deliveries for the next month as it upgrades a plant in Belgium.
New vaccines from Astrazeneca and Johnson & Johnson are being reviewed by regulators, but haven’t been approved in Canada.
Astrazeneca’s vaccine has been approved in the u.k. and India and is playing a significant role in vaccination efforts in those countries. Health Canada spokesperson Eric Morrissette said government regulators continue to look at the vaccine and have been receiving information from the company since last fall, but they don’t have a firm timeline for a decision.
“This review is being done through a rolling submission, where data is submitted by the manufacturer and reviewed by health Canada as it becomes available,” he said. “Additional data to support the quality, safety and efficacy of the vaccine are needed before a decision can be made.”
Johnson & Johnson’s candidate hasn’t reported any efficacy data publicly yet, but is also in a review with health Canada and has provided safety data from early clinical trials. It has a large clinical trial underway that is expected to release results within weeks. Crucially, the company’s vaccine requires only one dose to be effective, which would make distributing it much easier.
Astrazeneca’s vaccine, developed with Oxford university in the u.k., has much less stringent storage requirements and can be manufactured in more facilities around the world. The company estimates it can produce up to three billion doses of the vaccine.
dr. Supriya Sharma, health Canada’s chief medical adviser, was not available on Wednesday, but earlier this month, she said they were hoping to get more information from the company’s ongoing research.
“There is a large Astrazeneca study that’s ongoing in the united States, and we still are expecting to get some information from that study that’s almost 40,000 participants,” she said. “We’re working very closely with our international partners, but there’s still some questions to be sorted through before we make a final decision.”
Astrazeneca did a separate clinical trial last year that other countries have relied on to approve the vaccine. That trial, however, had a dosing error, where some participants were given two full doses while some were given a half dose combined with a full dose.
Overall, the vaccine was shown to be 70 per cent effective at preventing people from developing COVID, but the company started a second trial to gather more data without the error.
dr. Isaac Bogoch, an infectious disease physician and member of Ontario’s vaccine task force, said the dosing error is something that needs to be closely scrutinized.
“health Canada is doing the right thing by clearly taking their time to evaluate the vaccine. They’ve got it right. There should be no external pressure and no political interference,” he said. “That study was actually conducted in a very sloppy manner, and reported in a very sloppy manner.”
Bogoch said Canadians have to have confidence in the vaccines, because a shot people are reluctant to take doesn’t help the situation.
“These vaccines will only work if people take it and if people don’t have trust in the process or trust in the product, they’re not going to take the vaccine.”
Steven Kerfoot, an associate professor of immunology at Western university, Ont., said the problem with Astrazeneca’s trial is that it wasn’t complete.
“And so the expectation from Canada’s understanding is that they want to see a complete trial with efficacy and safety data built in.”
he said the error in the trial and some of the manufacturing issues that have slowed Pfizer vaccine deliveries this month are not uncommon in the industry, but usually the industry isn’t under such an intense global microscope.
“These are all things that happen with all drugs. And none of it, you can think of as unexpected.”
Pfizer and Moderna’s candidates were more than 90 per cent effective at preventing people from getting sick from the virus, but Kerfoot said if the new vaccines prove to be even 70 per cent effective, that’s a great result. He said the key is to get a high-level of protection in the population.
“We like to think of all medicine as being medicine for us individually, but vaccines are really best thought of as medicines for the population as a whole.”
Bogoch said more vaccines will be helpful and there are positive signs from both companies, but Canada has a secure supply already.
“Even if we don’t get access to Astrazeneca, and even if we hypothetically don’t get access to Johnson & Johnson, we’ll have enough vaccine between Moderna and Pfizer to vaccinate all of Canada.”
he said he understands the frustration, but the problem is not that Canada doesn’t have vaccines, the problem is that we don’t have them right now.
HEALTH CANADA IS DOING THE RIGHT THING BY CLEARLY TAKING THEIR TIME TO EVALUATE THE VACCINE.