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

Caledonia Secondary School is the recipient of a $50,000 grant to replace its aging science equipment. (File photo)
Cal snags major grant to modernize science equipment

The $50,000 comes from a pharmaceutical company

Unemployment rate drops in northwestern B.C.

Large improvement since Spring 2020

Uplands Nursery this year will do all of the 4600 Block of Lazelle Ave., beginning at its east end, and a portion of the 4700 Block. (File photo)
Lazelle sidewalk project begins June 14

Improvements coming to 4600 and 4700 Blocks

Cassie Hall Elementary School students pose for a picture in their garden. Since 2019, students and staff at the school have been attending to the garden project. (Binny Paul/Terrace Standard)
Cassie Hall students grow a green sanctuary at school

The K-6 elementary school students and staff have been working on the garden project since 2019

Glenn Bennett returns as chief councillor for Kitselas First Nation after June 10 elections. (Submitted photo)
Kitselas First Nation votes Glenn Bennett as chief councillor on June 10

Six council members were also elected from a packed pool of candidates

At an outdoor drive-in convocation ceremony, Mount Royal University bestows an honorary Doctor of Laws on Blackfoot Elder and residential school survivor Clarence Wolfleg in Calgary on Tuesday, June 8, 2021. THE CANADIAN PRESS/Jeff McIntosh
‘You didn’t get the best of me’: Residential school survivor gets honorary doctorate

Clarence Wolfleg receives honorary doctorate from Mount Royal University, the highest honour the school gives out

Two-year-old Ivy McLeod laughs while playing with Lucky the puppy outside their Chilliwack home on Thursday, June 10, 2021. (Jenna Hauck/ Chilliwack Progress)
VIDEO: B.C. family finds ‘perfect’ puppy with limb difference for 2-year-old Ivy

Ivy has special bond with Lucky the puppy who was also born with limb difference

A million-dollar ticket was sold to an individual in Vernon from the Lotto Max draw Friday, June 11, 2021. (Photo courtesy of BCLC)
Lottery ticket worth $1 million sold in Vernon

One lucky individual holds one of 20 tickets worth $1 million from Friday’s Lotto Max draw

“65 years, I’ve carried the stories in my mind and live it every day,” says Jack Kruger. (Athena Bonneau)
‘Maybe this time they will listen’: Survivor shares stories from B.C. residential school

Jack Kruger, living in Syilx territory, wasn’t surprised by news of 215 children’s remains found on the grounds of the former Kamloops Indian Residential School

A logging truck carries its load down the Elaho Valley near in Squamish, B.C. in this file photo. THE CANADIAN PRESS/Chuck Stoody
Squamish Nation calls for old-growth logging moratorium in its territory

The nation says 44% of old-growth forests in its 6,900-square kilometre territory are protected while the rest remain at risk

Flowers and cards are left at a makeshift memorial at a monument outside the former Kamloops Indian Residential School to honour the 215 children whose remains are believed to have been discovered buried near the city in Kamloops, B.C., on Monday, May 31, 2021. THE CANADIAN PRESS/Darryl Dyck
‘Pick a Sunday:’ Indigenous leaders ask Catholics to stay home, push for apology

Indigenous leaders are calling on Catholics to stand in solidarity with residential school survivors by not attending church services

“They will never be forgotten, every child matters,” says Sioux Valley Chief Jennifer Bone in a video statement June 1. (Screen grab)
104 ‘potential graves’ detected at site of former residential school in Manitoba

Sioux Valley Dakota Nation working to identify, repatriate students buried near former Brandon residential school

The Queen Victoria statue at the B.C. legislature was splattered with what looks like red paint on Friday. (Nicole Crescenzi/News Staff)
Queen Victoria statue at B.C. legislature vandalized Friday

Statue splattered with red paint by old growth forest proponents

Police cars are seen parked outside Vancouver Police Department headquarters on Saturday, January 9, 2021. THE CANADIAN PRESS/Darryl Dyck
Vancouver police officer charged with assault during an arrest in 2019

The service has released no other details about the allegations

Most Read