Skip to main content
The Globe and Mail
Support Quality Journalism.
The Globe and Mail
First Access to Latest
Investment News
Collection of curated
e-books and guides
Inform your decisions via
Globe Investor Tools
Just$1.99
per week
for first 24 weeks

Enjoy unlimited digital access
Enjoy Unlimited Digital Access
Get full access to globeandmail.com
Just $1.99 per week for the first 24 weeks
Just $1.99 per week for the first 24 weeks
var select={root:".js-sub-pencil",control:".js-sub-pencil-control",open:"o-sub-pencil--open",closed:"o-sub-pencil--closed"},dom={},allowExpand=!0;function pencilInit(o){var e=arguments.length>1&&void 0!==arguments[1]&&arguments[1];select.root=o,dom.root=document.querySelector(select.root),dom.root&&(dom.control=document.querySelector(select.control),dom.control.addEventListener("click",onToggleClicked),setPanelState(e),window.addEventListener("scroll",onWindowScroll),dom.root.removeAttribute("hidden"))}function isPanelOpen(){return dom.root.classList.contains(select.open)}function setPanelState(o){dom.root.classList[o?"add":"remove"](select.open),dom.root.classList[o?"remove":"add"](select.closed),dom.control.setAttribute("aria-expanded",o)}function onToggleClicked(){var l=!isPanelOpen();setPanelState(l)}function onWindowScroll(){window.requestAnimationFrame(function() {var l=isPanelOpen(),n=0===(document.body.scrollTop||document.documentElement.scrollTop);n||l||!allowExpand?n&&l&&(allowExpand=!0,setPanelState(!1)):(allowExpand=!1,setPanelState(!0))});}pencilInit(".js-sub-pencil",!1); // via darwin-bg var slideIndex = 0; carousel(); function carousel() { var i; var x = document.getElementsByClassName("subs_valueprop"); for (i = 0; i < x.length; i++) { x[i].style.display = "none"; } slideIndex++; if (slideIndex> x.length) { slideIndex = 1; } x[slideIndex - 1].style.display = "block"; setTimeout(carousel, 2500); } //

Lailamie Viloria, 48, a personal support worker at Fudger House Long Term Care home in Toronto receives a COVID-19 vaccine at St. Michael's Hospital in Toronto, Dec. 22, 2020.

Melissa Tait/The Globe and Mail

Administering the vast majority of Canada’s COVID-19 vaccine doses right away would avert significantly more coronavirus infections than reserving half of the country’s allotment as second doses for the first recipients, according to new modelling from researchers at the University of Toronto.

Yet some provinces – including Ontario – are planning to keep half of their initial shipments in the freezer in case the vaccine supply chain breaks down, meaning fewer vulnerable people will be inoculated in the early weeks of the vaccine campaign.

U of T’s projections came to light as Health Canada authorized Moderna, Inc.’s COVID-19 shot on Wednesday, making Canada just the second country to give a green light to two vaccines against the pandemic virus.

Story continues below advertisement

Canadian snowbirds older than 70 could receive vaccine in Florida within weeks

Indigenous leaders want immediate action on COVID-19 vaccine: federal NDP

Will governments be able to mandate the COVID-19 vaccine for health care workers?

The approval of Moderna’s shot adds urgency to the question of whether provincial governments should hold back half of their shots. That’s because the Moderna vaccine, which is easier to store and transport than the Pfizer-BioNTech shot, is set to be distributed widely in nursing homes, where the vaccines will be in a life-and-death race against a surging coronavirus.

“The thing that will best protect people against short-term illness and outbreaks and save lives is getting the first dose into as many people as you can,” said Allison McGeer, an infectious-disease physician at Sinai Health System and a member of the federal government’s COVID-19 immunity task force.

Dr. McGeer said that fact only became clear in the past week or two, as Pfizer-BioNTech and Moderna released data from their late-stage clinical trials showing the first dose conferred relatively strong protection against COVID-19 disease, at least in the short run.

Both vaccines are given as two injections either 21 or 28 days apart. In Moderna’s case, the vaccine was 50.8-per-cent efficacious in the two weeks after the first dose, and 92.1-per-cent efficacious after 14 days from the first dose, but before the second jab.

The second dose, Dr. McGeer and other experts agree, is crucial to ensuring immunity lasts as long as possible. They say everyone should get the second dose on schedule, but if supply issues delay that injection by a week or two, it shouldn’t hamper how well the vaccines work.

Ashleigh Tuite, an epidemiologist at U of T’s Dalla Lana School of Public Health who worked on the new modelling, said she and her colleagues projected that frontloading vaccine doses would avert between 34 and 42 per cent more symptomatic coronavirus infections, compared with a strategy of keeping half the shipments in reserve.

“It makes much more sense to just get as many people their first doses as soon as possible,” Dr. Tuite said.

Story continues below advertisement

On Tuesday, Dr. Tuite presented her projections to a meeting of Ontario’s COVID-19 Science Advisory Table, which is preparing to make a formal recommendation to the government on whether to hold back the second doses.

Peter Juni, scientific director of the science table and a professor of medicine and epidemiology at U of T, said his personal view is that it is “absolutely justifiable” from a scientific perspective to inject the available doses as soon as possible, and count on future shipments to supply the follow-up dose.

The decision ultimately comes down to risk management, and to how much the provincial government trusts the vaccine supply, he added.

Nova Scotia, Saskatchewan and British Columbia have said they won’t hold back doses, while other provinces have decided to reserve some vials or are still working out their plans.

“I have a real challenge leaving vaccine in a fridge when there are so many people at risk right now,” British Columbia’s Provincial Health Officer Bonnie Henry said earlier this month.

In Ontario’s case, a spokeswoman for Health Minister Christine Elliott declined to answer questions about whether the government would change its publicly stated approach and start administering all of the vaccines that it receives from the federal government right away.

Story continues below advertisement

“While some individuals may have good COVID-19 immunity after only one dose, it’s not guaranteed and a second dose is necessary,” Alexandra Hilkene said in a statement.

She referred The Globe And Mail to previous statements from retired general Rick Hillier, chair of Ontario’s vaccine task force, who said in early December that the province would hold back 50 per cent of the first shipments of the vaccines in order to ensure that the second shots are available for individuals at the correct time interval.

Ontario is expecting to receive 53,000 doses of the Moderna vaccine the week of Dec. 28. The first shots are destined for long-term care homes in hard-hit parts of the Greater Toronto Area, Ms. Hilkene said.

If all of those doses were injected right away, more than half of the residents of Ontario’s approximately 79,000 long-term beds would have some vaccine-induced protection against COVID-19 by the middle of January.

Major-General Dany Fortin, the federal government’s point person on distributing vaccines, said Wednesday that provinces shouldn’t be concerned about the reliability of the vaccine shipments in the coming weeks.

“We have no reason to [have] doubt on the distribution of the product. It’s been progressing very well to date,” he told reporters at a press conference in Ottawa.

Story continues below advertisement

Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.

Your Globe

Build your personal news feed

  1. Follow topics and authors relevant to your reading interests.
  2. Check your Following feed daily, and never miss an article. Access your Following feed from your account menu at the top right corner of every page.

Follow the authors of this article:

Follow topics related to this article:

View more suggestions in Following Read more about following topics and authors
Coronavirus information
Coronavirus information
The Zero Canada Project provides resources to help you manage your health, your finances and your family life as Canada reopens.
Visit the hub
Report an error Editorial code of conduct
Due to technical reasons, we have temporarily removed commenting from our articles. We hope to have this fixed soon. Thank you for your patience. If you are looking to give feedback on our new site, please send it along to feedback@globeandmail.com. If you want to write a letter to the editor, please forward to letters@globeandmail.com.

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff. Non-subscribers can read and sort comments but will not be able to engage with them in any way. Click here to subscribe.

If you would like to write a letter to the editor, please forward it to letters@globeandmail.com. Readers can also interact with The Globe on Facebook and Twitter .

Welcome to The Globe and Mail’s comment community. This is a space where subscribers can engage with each other and Globe staff.

We aim to create a safe and valuable space for discussion and debate. That means:

  • Treat others as you wish to be treated
  • Criticize ideas, not people
  • Stay on topic
  • Avoid the use of toxic and offensive language
  • Flag bad behaviour

If you do not see your comment posted immediately, it is being reviewed by the moderation team and may appear shortly, generally within an hour.

We aim to have all comments reviewed in a timely manner.

Comments that violate our community guidelines will not be posted.

Read our community guidelines here

Discussion loading ...

To view this site properly, enable cookies in your browser. Read our privacy policy to learn more.
How to enable cookies