In this May 25, 2020, file photo, a lab technician extracts a portion of a COVID-19 vaccine candidate during testing at the Chula Vaccine Research Center, run by Chulalongkorn University in Bangkok, Thailand. THE CANADIAN PRESS/AP-Sakchai Lalit

How many Canadians will need to get vaccinated against COVID-19? Officials aren’t sure

Canada has secured contracts for four potential vaccines

Although Canada has secured four contracts for more 190 million doses of potential COVID-19 vaccines, health officials aren’t sure how many people will need to receive it.

Deputy public health officer Dr. Howard Njoo said Tuesday (Sept. 1) that the level of vaccination to achieve community, or herd, protection varies by the disease.

“That’s still to be determined because the science is not clear on that yet,” Njoo said.

“For a very contagious disease like measles the vaccine uptake needs to be much higher to determine that level of community protection. We don’t know that yet for COVID-19.”

There are currently at least 128,948 total test positive cases of the virus in Canada, with more than 9,100 deaths.

For measles, the Canadian government has a goal of 95 per cent vaccination by 2025. According to John Hopkins University, early estimates of the virus’s infectiousness point to at least 60 to 70 per cent of the population needing to be vaccinated to achieve herd protection. A recent poll suggests that about 14 per cent of Canadians will not get the vaccine altogether, while nearly one-third will adopt a “wait and see” approach.

It’s also unclear how effective an eventual vaccine will be.

“International consensus is that we should at least look at vaccines that are around the 50 per cent vaccine efficacy mark,” chief public health officer Dr. Theresa Tam said, echoing similar statements from other public health researchers.

“This means that an individual who was vaccinated would be 50 per cent less likely to get COVID disease—or whatever the particular endpoint is that’s measured in the trial—than individuals that weren’t vaccinated,” said Dr. Ruth Karron, who leads the Center for Immunization Research at the Johns Hopkins Bloomberg School of Public Health.

But Canadian health officials were sure on one point; going for a herd immunity approach by letting the disease run through the population was not effective. Tam called it an “extremely difficult strategy” because of the potential for exponential growth that could overwhelm health-care systems.

“What we do know that even in the most [COVID-19] affected parts of the world, the level of population immunity seems quite low, so getting high enough vaccine uptake is going to be quite important,” Tam said.

Currently, Canada has agreements with Johnson & Johnson, Novavax, Pfizer and Moderna, if any of the four companies develop an effective vaccine. Any vaccine will have to be approved by Health Canada before Canadians can get it.

READ MORE: Canada signs deals with two suppliers for potential COVID-19 vaccines

READ MORE: 30% of British Columbians would ‘wait and see’ before taking COVID vaccine: poll


@katslepian

katya.slepian@bpdigital.ca

Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Coronavirusvaccines

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

There has been COVID-19 exposures at two elementary schools in District 42. (Image courtesy CDC)
Interior Health reports 24 additional COVID-19 cases

This includes three school exposures in Kelowna

One person was killed in a two-vehicle crash south of Williams Lake on Highway 97 Wednesday, Oct. 28, 2020. (Photo submitted)
Highway 97 crash south of Williams Lake claims one life

Road conditions at the time were slippery and covered with slush: RCMP

Fraser-Nicola BC Liberal Party candidate Jackie Tegart with supporters on the Ashcroft bridge, Oct. 21, 2020. Tegart is the frontrunner in the riding after the initial vote count, with mail-in ballots to be counted starting on Nov. 6. (Photo credit: Barbara Roden)
Liberal incumbent Jackie Tegart holds narrow lead over Aaron Sumexheltza of NDP

Initial count is complete, and mail-in ballots will determine who wins in Fraser-Nicola

John Horgan has been re-elected the MLA for Langford-Juan de Fuca. (File-Black Press)
Horgan trounces challengers to be re-elected in his Vancouver Island riding

MLA has represented constituency of Langford-Juan de Fuca and its predecessors since 2005

B.C. Green Party leader Sonia Furstenau outlines her party's climate action platform at Nanaimo's Vancouver Island Conference Centre earlier this month. (News Bulletin file photo)
Green leader Furstenau declared victor in her home riding on Vancouver Island

Cowichan Valley voters elect freshly minted party leader for her second term

Provincial health officer Dr. Bonnie Henry arrives for briefing on the COVID-19 situation, B.C. legislature, Oct. 26, 2020 (B.C. government)
B.C. records 217 more COVID-19 cases, mask use urged

Infection spike continues, 21 senior facilities affected

A raccoon paid a visit to a Toronto Tim Hortons on Oct. 22, 2020. (shecallsmedrew/Twitter)
Who are you calling a trash panda? Raccoon takes a shift at Toronto Tim Hortons

Tim Hortons said animal control was called as soon they saw the surprise visitor

The duffel bags were found to contain 84 pounds of cocaine, valued at approximately $1.2 million and 198 pounds of methamphetamine, valued at approximately $960,000. Photo courtesy U.S. Customs and Border Protection.
2 men accused of fleeing border agents near U.S.-B.C. border with $2M in drugs

Cocaine and methamphetamine seized by U.S. law enforcement in remote Idaho area near Canadian border

Pixabay photo
‘Horrific’ abuse of volunteers, staff by parents must stop: Chilliwack soccer club

Parents have become abusive after being told COVID-19 rules, email says

FILE – The Queen of Alberni ferry leaves the Tsawwassen Ferry Terminal in Delta bound for Vancouver Island, Sunday, July 29, 2007. (CP PHOTO/Richard Lam) CANADA
Mechanical failure leaves nearly 200 passengers stranded on BC Ferries ship for hours

A tug arrived after dark to safely nudge the vessel into a berth so travellers could finally disembark

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

Ridge Meadows RCMP (Black Press)
Maple Ridge X-ray tech convicted of sexual assault dating back 30 years

Allen James Brooks is expected to be sentenced in January 2021

BC Liberal Leader Andrew Wilkinson leaves the stage after announcing he is stepping down as party leader, during a news conference in Burnaby, B.C., on Monday, October 26, 2020. THE CANADIAN PRESS/Darryl Dyck
Too rural, not enough diversity, soul searching needed, say BC Liberals

Elections BC says there are about 600,000 mail-in and absentee ballots across the province still to count

Prime Minister Justin Trudeau makes his way to provide an update on the COVID pandemic in Ottawa on Tuesday, Oct. 27, 2020. Canada has reached a grim milestone in the COVID-19 pandemic, surpassing 10,000 novel coronavirus deaths. THE CANADIAN PRESS/Sean Kilpatrick
Alberta COVID deaths pushes Canada past milestone of 10,000 deaths

Canada crossed the threshold of 5,000 deaths on May 12, a little over two months after the first was reported

Most Read