A nurse prepares to give the first COVID-19 vaccine to be distributed in Edmonton on Dec. 15, 2020. THE CANADIAN PRESS/Jason Franson

A nurse prepares to give the first COVID-19 vaccine to be distributed in Edmonton on Dec. 15, 2020. THE CANADIAN PRESS/Jason Franson

Experts say stretching out time between COVID-19 vaccine doses in Alberta reasonable

Pfizer-BioNTech vaccine’s label says doses should be given 21 days apart and Moderna’s calls for a 28-day gap

Infectious disease experts say it makes sense for Alberta to stretch the amount of time between first and second doses beyond what’s spelled out on the labels of the two approved COVID-19 vaccines.

“I think it makes practical sense for the short term,” said Dr. Jim Kellner, a researcher and professor with the University of Calgary’s Cumming School of Medicine.

Dr. Lynora Saxinger, associate professor with the University of Alberta’s Department of Medicine, called the move “completely justifiable,” though she understands why some people are worried that the practice hasn’t been studied.

The Pfizer-BioNTech vaccine’s label says doses should be given 21 days apart and Moderna’s calls for a 28-day gap.

Dr. Deena Hinshaw, Alberta’s chief medical officer of health, said Tuesday the province is allowing doses to be booked up to 42 days apart, though long-term care residents will still receive theirs in the shorter window.

She said it wasn’t an easy decision.

“If we were to save half of every vaccine shipment for those who need a second dose, we would be dramatically reducing the total number of Albertans who could benefit from the early protection,” she said.

The National Advisory Committee on Immunization says prolonging the wait to 42 days is acceptable in places where there’s high community transmission, strain on the health-care system and limited vaccine supply — as is the case in Alberta.

Health Minister Tyler Shandro said Wednesday on Twitter that due to a shortage of supply, about 2,000 planned vaccinations for continuing care residents did not happen this week. The number of available appointments was also reduced in some areas.

There were 820 Albertans hospitalized with COVID-19 as of Wednesday, including 137 in intensive care. There were also 875 new cases detected over the past day and 5.3 per cent of tests came back positive.

Kellner, who is part of the national COVID-19 Immunity Task Force and also advises on provincial panels, said the longer timeline would be “reasonable” until the end of February, when Ottawa expects to significantly ramp up deliveries to the provinces.

But he said it’s not something he’d recommend doing indefinitely without further evidence.

“People are trying to balance doing the right thing for every individual who is in need of vaccine and … doing the right thing for the greater good for the whole population. And that’s always a challenge.”

Saxinger said while there’s little direct evidence about altering the vaccine dose schedule, experience with other vaccines suggests it’s not a problem. In some cases, immune responses benefit from a longer wait, she said.

“You have a bit of a more mature memory response to it.”

Data suggest both approved vaccines are 92 per cent effective two weeks after the first doses, but it’s not clear how long that protection lasts.

After a second dose, protection rises to 94.5 for the Pfizer-BioNTech vaccine and 94 per cent with the Moderna one.

Saxinger added that on average, antibody levels from the first dose are about four times higher than in those who recovered from COVID-19.

“Those things together are pretty reassuring,” she said, adding it’s “extremely” unlikely antibody levels that high would drop quickly in a matter of weeks.

She said modelling has been done of different scenarios.

“How many lives do you save if you give more first doses and circle back with the second dose, versus going for the very strict time schedule that’s been studied more thoroughly?” she said.

“All the models have shown that you save more lives with a bit of flexibility on the second dose timing.”

Health officials in Manitoba and Saskatchewan said they’re sticking with the time frame set out on the vaccine manufacturers’ labels for now. British Columbia plans to give the second shots 35 days later. Quebec has not set out a timeline for its follow-up doses.

Lauren Krugel, The Canadian Press

Like us on Facebook and follow us on Twitter.

Want to support local journalism? Make a donation here.

Coronavirus

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

Just Posted

The Cariboo Regional District will provide a grant in aid to the Charlotte Lake Landowners and Leaseholders Association to purchase an AED. (Anne Kohut photo)
Remote Charlotte Lake residents prepare for medical emergencies

Many of the local residents are elderly, said landholders association president Anne Kohut

Buses transport School District 27 students home after school on Monday, Jan 25, 2021 in Williams Lake. (Anna Fait photo - Williams Lake Tribune)
COVID-19: More contact tracing, more Williams Lake students self-isolating in SD27

Interior Health answers questions around contact tracing

Toronto Public Health nurse Lalaine Agarin makes preparations at Toronto’s mass vaccination clinic, Jan. 17, 2021. THE CANADIAN PRESS/Frank Gunn
3 deaths, 234 new cases of COVID-19 in Interior Health over the weekend

One death connected to outbreak at Kamloops’ Royal Inland Hospital, where 20 patients and 28 staff have tested positive

The Williams Lake Seniors Village. (Angie Mindus file photo - Williams Lake Tribune)
COVID-19 outbreak declared over at Williams Lake Seniors Village: Interior Health

IH credited the good work of staff in keeping the outbreak from spreading

Crews with Discovery Channel film as an Aggressive Towing driver moves a Grumman S2F Tracker aircraft around a 90-degree turn from its compound and onto the road on Saturday, Jan. 23, 2021. It was the “most difficult” part of the move for the airplane, one organizer said. (Jenna Hauck/ Chilliwack Progress)
VIDEO: Vintage military plane gets towed from Chilliwack to Greater Victoria

Grumman CP-121 Tracker’s eventual home the British Columbia Aviation Museum on Vancouver Island

Kamloops This Week.
48 COVID-19 cases and one death associated with outbreak at Kamloops hospital

One of the 20 patients infected has died, meanwhile 28 staff with COVID-19 are isolating at home

Cannabis bought in British Columbia (Ashley Wadhwani/Black Press Media)
Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Rolling seven-day average of cases by B.C. health authority to Jan. 21. Fraser Health in purple, Vancouver Coastal red, Interior Health orange, Northern Health green and Vancouver Island blue. (B.C. Centre for Disease Control)
2nd COVID vaccine doses on hold as B.C. delivery delayed again

New COVID-19 cases slowing in Fraser Health region

Provincial health officer Dr. Bonnie Henry talk about the next steps in B.C.’s COVID-19 Immunization Plan during a press conference at Legislature in Victoria, B.C., on Friday, January 22, 2021. Two more cases of the COVID-19 strain first identified in South Africa have been diagnosed in British Columbia, bringing the total to three as of Jan. 16.THE CANADIAN PRESS/Chad Hipolito
B.C. now has three cases of South African COVID-19 variant, six of U.K. strain

Both variants are thought to spread faster than earlier strains

Rodney and Ekaterina Baker in an undated photo from social media. The couple has been ticketed and charged under the Yukon’s <em>Civil Emergency Measures Act</em> for breaking isolation requirements in order to sneak into a vaccine clinic and receive Moderna vaccine doses in Beaver Creek. (Facebook/Submitted)
Great Canadian Gaming CEO resigns after being accused of sneaking into Yukon for vaccine

Rod Baker and Ekaterina Baker were charged with two CEMA violations each

Police discovered a makeshift nightclub in a Vancouver apartment on Jan. 23, 2021, and say it wasn’t the first time this month officers have been called to the unit over social gathering concerns. (Phil McLachlan - Capital News)
Doorman of makeshift ‘booze-can’ in Vancouver apartment fined; police look to court order

This marks the fourth complaint about social gatherings inside the apartment in January

A Kelowna couple welcomed their Nooner baby in December. (Flytographer)
Kelowna couple welcomes baby girl from Hotel Zed Nooner campaign

Nicole and Alex will now have 18 years of free stays at the hotel

Kyrell Sopotyk was drafted by the Kamloops Blazers in 2016 and played two seasons with the Western Hockey League club. (Photograph By ALLEN DOUGLAS/KTW)
Kamloops Blazer paralyzed in snowboarding accident sparks fundraiser for family

As of Jan. 24, more than $68,000 had been raised to help Kamloops Blazers’ forward Kyrell Sopotyk

Most Read