A vial of AstraZeneca vaccine is seen at a mass COVID-19 vaccination clinic in Calgary, Alta., on April 22, 2021. THE CANADIAN PRESS/Jeff McIntosh

A vial of AstraZeneca vaccine is seen at a mass COVID-19 vaccination clinic in Calgary, Alta., on April 22, 2021. THE CANADIAN PRESS/Jeff McIntosh

AstraZeneca expiry change based on science but communication is key: experts

Medical advisor said decision made after AstraZeneca submitted data supporting the change

Many immunologists and infectious disease experts are rushing to convince Canadians that extending the expiration date on some Oxford-AstraZeneca doses is a normal and scientifically sound decision.

Health Canada said Saturday it had approved adding another month to the shelf life of two lots of Oxford-AstraZeneca vaccine that were due to expire Monday.

Ontario asked the company if the change could happen to save up to 45,000 doses that were expiring, but the decision affects remaining doses from the two affected lots in every province. Fewer than 100,000 doses are left from those two lots.

Health Canada’s chief medical adviser, Dr. Supriya Sharma, said in an interview with The Canadian Press Monday that the decision was made after AstraZeneca submitted data supporting the change last week.

That included the results of testing doses from the two lots that were expiring, and modelling data from the company that showed the doses would remain stable for at least the next month.

“We’ve been really clear that we’re making decisions based only on science and evidence, and this is no exception,” Sharma said.

But the decision to adjust the expiration date at the 11th hour on the weekend led many Canadians to express frustration and concern about whether it was truly being made because of science, or because of a policy failure to use the doses in time.

“The feedback I’m getting is this idea that it was done out of desperation,” said Timothy Caulfield, the Canada Research Chair in health law and policy at the University of Alberta.

“That’s the way it looks from the outside. It’s a really good example of why context matters.”

Pharmacologist Sabina Vohra-Miller, founder of the science communication website Ambiguous Science, said it is not uncommon at all for companies to get calls from pharmacies asking if a patient can use their drug beyond the expiration.

“Most of the time when these expiry dates are extended, people don’t get to know about it,” she said.

She said vaccines and other medications are tested constantly to determine how they perform in various scenarios, including past their expiration.

“For all we know we might next year find out that based on long-term shelf life studies that in fact the vaccines are totally OK for an entire year, so maybe for future batches the expiry date will be a year,” she said. “We just don’t know this yet, because these vaccines are so new.”

AstraZeneca, Pfizer-BioNTech and Moderna all have six-month life spans at the moment, if stored properly. That means in a fridge for AstraZeneca, an ultralow temperature freezer for Pfizer and a normal freezer for Moderna.

The Johnson & Johnson vaccine, the only other one authorized by Health Canada though it’s not in use here yet, can be stored frozen for up to two years.

Sharma said there are no other requests to adjust expirations for COVID-19 vaccines, but also noted that doses expiring is not a big issue when people still want more doses than we have in our supply.

It was an issue for these doses because Ontario had paused the use of AstraZeneca while awaiting more data on the risk of vaccine-induced blood clots. It is now using them only for second doses but didn’t decide to proceed with second doses early enough to avoid the risk the expiring doses would go to waste.

Sharma said she can understand the perception that the decision was made out of desperation but said that is not something Health Canada would do.

“I mean, I think it would have been better if the submission came to us earlier,” she said. “It only came to us on May 27. And so we looked at it as soon as we could. If that data did not support the extension, we would have said no.”

Caulfield said communicating scientific decisions in a pandemic is really hard, but doing it well is also critical.

“When I first heard this story my immediate reaction was anything that invites doubt, anything that injects more skepticism into the calculus, for those that are sitting on the fence (about getting vaccinated) is problematic,” he said.

More than two-thirds of eligible Canadians are now vaccinated with at least one dose. Caulfield said Canada is getting close to what he calls the “hesitancy hurdle” where the people not yet vaccinated may need some convincing.

The impact of framing how we talk about vaccines matters “more and more” right now, he said.

Dr. Allison McGeer, an infectious disease consultant at Mount Sinai Hospital in Toronto, said the change to the vaccine expiry is a normal part of the process and should not be viewed with alarm.

“Yeah, it will come at the last minute but that’s that’s a pandemic thing,” she said. “I have absolute faith in Health Canada, that they know what they’re doing, and that we have solid processes for managing this and extending expiry dates. This isn’t anything out of the ordinary.”

—Mia Rabson, The Canadian Press

RELATED: Health Canada extends expiry of thousands of AstraZeneca shots by another month

Coronavirusvaccines

Just Posted

Christina Lake Fire Department’s Chief Joe Geary eyes the camera from behind the wheel of the department’s 40-year-old bush truck. Photo: Laurie Tritschler
Christina Lake FD needs new equipment, upgrades, prompting loan by RDKB

It’s not whether the department needs the equipment, it’s how voters will pay for it, says Regional District

Adrian Moyls is the Selkirk College Class of 2021 valedictorian and graduate of the School of Health and Human Services. Photo: Submitted
Selkirk College valedictorian proves mettle in accomplishment

Adrian Moyls is a graduate of the School of Health and Human Services

Selkirk College has begun its search in earnest for a leader to replace president Angus Graeme who is set to retire from his position in May 2022. Photo: Submitted
Selkirk College seeks community input for president search

Current president Angus Graeme retires next year

A report shows nine West Kootenay communities are have more low-income persons than the provincial average. File photo
Study casts new light on poverty in the West Kootenay

Nine communities in region have more low-income residents than provincial average

A tent housing a mobile vaccination clinic. (Interior Health/Contributed)
Over 5K jabbed at Interior Health mobile COVID-19 vaccine clinics

The clinics have made stops in more than 40 communities since launching last week

Marco Mendicino, Minister of Immigration, Refugees and Citizenship during a press conference in Ottawa on Thursday, May 13, 2021. THE CANADIAN PRESS/Sean Kilpatrick
Canada to welcome 45,000 refugees this year, says immigration minister

Canada plans to increase persons admitted from 23,500 to 45,000 and expedite permanent residency applications

Emily Steele holds up a collage of her son, 16-year-old Elijah-Iain Beauregard who was stabbed and killed in June 2019, outside of Kelowna Law Courts on June 18. (Aaron Hemens/Capital News)
Kelowna woman who fatally stabbed teen facing up to 1.5 years of jail time

Her jail sentence would be followed by an additional one to 1.5 years of supervision

Cpl. Scott MacLeod and Police Service Dog Jago. Jago was killed in the line of duty on Thursday, June 17. (RCMP)
Abbotsford police, RCMP grieve 4-year-old service dog killed in line of duty

Jago killed by armed suspect during ‘high-risk’ incident in Alberta

The George Road wildfire near Lytton, B.C., has grown to 250 hectares. (BC Wildfire Service)
B.C. drone sighting halts helicopters fighting 250 hectares of wildfire

‘If a drone collides with firefighting aircraft the consequences could be deadly,’ says BC Wildfire Service

A dose of the Pfizer-BioNTech COVID-19 vaccine is pictured at a vaccination site in Vancouver Thursday, March 11, 2021. THE CANADIAN PRESS/Jonathan Hayward
NACI advice to mix vaccines gets varied reaction from AstraZeneca double-dosers

NACI recommends an mRNA vaccine for all Canadians receiving a second dose of a COVID-19 vaccine

A aerial view shows the debris going into Quesnel Lake caused by a tailings pond breach near the town of Likely, B.C., Tuesday, Aug. 5, 2014. THE CANADIAN PRESS/Jonathan Hayward
Updated tailings code after Mount Polley an improvement: B.C. mines auditor

British Columbia’s chief auditor of mines has found changes to the province’s requirements for tailings storage facilities

A North Vancouver man was arrested Friday and three police officers were injured after a 10-person broke out at English Bay on June 19, 2021. (Youtube/Screen grab)
Man arrested, 3 police injured during 10-person brawl at Vancouver beach

The arrest was captured on video by bystanders, many of whom heckled the officers as they struggled with the handcuffed man

Patrick O’Brien, a 75-year-old fisherman, went missing near Port Angeles Thursday evening. (Courtesy of U.S. Coast Guard)
Search for lost fisherman near Victoria suspended, U.S. Coast Guard says

The 75-year-old man was reported missing Thursday evening

Most Read