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
Cancel Anytime
Enjoy Unlimited Digital Access
Get full access to globeandmail.com
Just $1.99per week for the first 24weeks
Just $1.99per week for the first 24weeks
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); } //

Farang Ahmadkorour, left, 92, receives her COVID-19 vaccine at the Seneca College mass vaccination site during the COVID-19 pandemic in Toronto on April 6, 2021.

Nathan Denette/The Canadian Press

A national panel of experts is continuing to recommend that second doses of COVID-19 vaccinations can wait up to four months, a position that places Canada among countries with the longest delays between shots.

The National Advisory Committee on Immunization (NACI) provided the guidance Wednesday in a 41-page report, saying current evidence shows that a single dose offers good protection and will “allow faster population-level protection” that would thwart the spread of the virus. At the same time, the committee’s report said it anticipates that most people will not have to wait that long as supplies ramp up.

The four-month recommendation was first made last month. The country’s public-health officers sent out a statement Wednesday saying that the population benefits of the four-month delay outweigh individual risk. Canada currently only has enough vaccines to offer first-dose coverage to just more than one-quarter of the population.

Story continues below advertisement

“A number of countries are using three-months intervals. I think Canada might be the only one using a four-month interval,” said Shelley Deeks, a communicable-disease specialist and NACI vice-chair. “But we’ve emphasized our recommendation is up to four months. What we are expecting to see as the provinces and territories roll out programs is that this period of time can actually decrease as more and more people are getting vaccinated.”

Tracking Canada’s COVID-19 vaccine rollout plans: A continuing guide

Pfizer’s upcoming hike in vaccine deliveries to Canada sets stage for mass vaccination sites

The U.S. Centres for Disease Control has said second doses can wait up to 42 days. In Britain, second doses can be administered up to three months after the first.

Eleanor Fish, a professor of immunology at the University of Toronto, said accumulating evidence shows that Canadian vaccination campaigns should stick to the manufacturers’ recommended schedules of three or four weeks between doses, at the very least for people more than 55 years old and those who are immunocompromised.

With the four-month gap, “we’re really talking about partial protection, which we don’t know how long it will last,” Dr. Fish said. “But the point is, when you get a second dose within the time frame the trials examined, there is no question you get an excellent response.”

The NACI recommendation has real-world consequences for vulnerable people anxiously awaiting a second shot.

On Wednesday afternoon, Pina Rotilio met her parents, Frank and Maria Menniti, on the front stoop of their Toronto home to deliver their grocery supply. The couple received a first dose of vaccine March 10 but second doses scheduled for April were cancelled.

Maria and Frank Menniti outside their home in Toronto on April 7, 2021.

Tijana Martin/The Globe and Mail

Mr. and Mrs. Menniti, aged 95 and 89, respectively, cancelled home care to avoid the risk of infection when the pandemic began. Mrs. Menniti does the heavy lifting around the house, despite arthritic hands. Mr. Menniti used to get home care to help him shower but Mrs. Menniti does it now. She turns 90 next week.

Story continues below advertisement

“I feel very lonely. I’m so tired,” Mrs. Menniti said. “I’d really like to get that second vaccination and have my daughter come and help me. I can’t do it any more. My husband can’t do nothing. Nobody can come inside.”

Their daughter, Ms. Rotilio, will get her first shot on the weekend, but nobody feels comfortable mixing indoors until her parents have two doses.

“We would still wear masks to protect them, but if they were fully vaccinated, I think we would be okay with partially vaccinated caregivers,” Ms. Rotilio said.

Mr. and Mrs. Menniti received the Pfizer-BioNTech vaccine. The NACI summary of the evidence for people more than 70 says that the vaccine showed anywhere from 58-per-cent-to-63-per-cent efficacy at preventing symptomatic illness and are 65 per cent to 83 per cent effective at preventing hospital admissions after one dose. There was no breakdown for 90-year-olds.

Dr. Fish points out that the Pfizer and Moderna vaccines are different than traditional antibody vaccines that often provide good protection after one dose. The new vaccines require a prime and booster to get to full protection.

She is also concerned, she said, that partial immunity might encourage the development of new variants.

Story continues below advertisement

Preliminary studies have recently questioned whether a single dose offers sufficient immunity to the elderly and cancer and transplant patients. The NACI recommendation took note of those studies, but added that there is limited “efficacy data on two-dose series in those populations” because they were not included in clinical trials.

Dr. Fish emphasized, however, that no clinical trials prove the efficacy of a four-month gap, either. The vaccine companies will soon release information on how long immunity lasts. “Importantly, Canada will have to examine the longevity of the response to this revised dosing schedule, in terms of when we give a booster, as we have not followed protocol,” she said.

Ontario, Alberta aim to speed up vaccinations as Moderna vaccine starts arriving

Ontario has given second doses to all nursing-home residents but not the elderly outside care settings. Other provinces, such as Quebec and British Columbia, have generally only given single doses so far.

Ontario followed the recommendations of its own Vaccine Clinical Advisory Group to stick to the manufacturers’ recommended dose intervals of three to four weeks for some immunocompromised people, including transplant and some cancer patients. It recommended extending second doses for the elderly outside care settings.

The NACI report said growing vaccine stockpiles should allow provinces to shorten the delay. “Every province can modulate second doses according to their supplies, and shorten the interval for older people,” said NACI chair and infectious-disease specialist Caroline Quach-Thanh. “But for now, the data is reassuring.”

With a report from Tijana Martin

Story continues below advertisement

Sign up for the Coronavirus Update newsletter to read the day’s essential coronavirus news, features and explainers written by Globe reporters and editors.

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 author of this article:

Follow topics related to this article:

View more suggestions in Following Read more about following topics and authors
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.

UPDATED: 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