Ontario’s COVID-19 science advisory table is warning Premier Doug Ford that the variant that first emerged in India, known as B.1.617, presents 'a significant unknown'
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Will Health Canada’s decision to grant an extension to the best-before date on thousands of AstraZeneca COVID-19 vaccine doses further spook public confidence in the troubled shots, or is there nothing really magical about drug expiry dates?
The drug regulator offered few details Saturday when it announced it was granting a one-month extension to the shelf life of two lots of AstraZeneca’s vaccines totalling about 49,000 doses. Any injections formerly set to expire Monday could now be used until July 1, the agency said.
In a three-paragraph statement Saturday, Health Canada said a submission from AstraZeneca “demonstrated that the quality, safety and efficacy of the two lots would be maintained for an extra month,” for a total of seven months, from the originally approved six months — an extension that would allow the provinces and territories to use up existing inventory “and provide Canadians access to much needed doses of the vaccine,” the agency said.
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In early May, Maj.-Gen. Dany Fortin, then head of the national vaccine rollout, said there were 250,000 AstraZeneca doses left in the country, with most of them expiring at the end of June.
Some critics said granting an extension two days before an expiry date inspires little trust. “Doses just a couple days away from the manufacturer’s expiry magically got an extra month of life,” University of Ottawa professor of law Amir Attaran said on social media, noting that the World Health Organization, in a May 17 statement, recommended that any COVID-19 vaccine that has passed its expiry date should not be administered. “Expiry dates do not affect the safety of the vaccine,” the agency noted, “rather are related to the potency or amount of protection the vaccine gives.”
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“I am very pro-vaccine and swallow expired pills sometimes. But biological drugs are different,” said Attaran, who has a PhD in immunology. “If you are going to be vaccinated, I recommend you ask to see the expiry date on the vial, and don’t accept anything offered after it.”
Health Canada, in a statement to the Post, said its authorization of an extended expiry date isn’t in conflict with the WHO’s position.
“Health Canada agrees with the World Health Organization that expired vaccine should not be used and any expired doses should be disposed of safely,” the department said.
However, “the shelf-life of vaccines may be extended if scientific evidence is provided to regulatory authorities to approve such extension. It is not unusual for the shelf-life of vaccines, or other drug products, to be extended based on updated scientific data, especially in scenarios where there is a high medical need.”
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The shelf-life extension applies only to the two specific lots, the department added, “and does not apply to other lots of the AstraZeneca vaccine.”
Last week, Ontario un-paused its temporary halt of AstraZeneca, and announced it would start giving out seconds doses to those who received their first shots in March, in a bid to use up the province’s stockpile before it expires. (Most provinces paused the use of the vaccine for first doses earlier this month over the risk of rare, but potentially fatal, blood clots.)
The shots were further held up during a quality assurance check that left only a few days for pharmacists to scramble to administer them.
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To some, the federal messaging, or rather, lack of it, just further muddied the waters.
“If this is an evidence-based decision (and I’m assuming it is) then the key will be to frame the explanation in a way that is transparent and retains confidence,” Timothy Caulfield, Canada Research Chair in health law and policy at the University of Alberta, said in an email to the National Post Sunday.
Conflicting messaging is less-than-ideal, he said — “as we saw with early AZ recommendations.”
Dr. Isaac Bogoch said that, as far as he could tell, Health Canada and AstraZeneca looked at a representative sample of the lots that were about to expire and stability data from a sample of those vaccines, and deemed it acceptable and safe to extend the expiration date by a month.
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“That sounds reasonable to me,” said Bogoch, an infectious disease specialist and member of Ontario’s COVID-19 vaccine distribution task force. “If I was going to instill confidence in the process I would communicate as much as I possibly could — ‘this is what we did, this is how we did it, this is how we came to the conclusion, this is why we feel the vaccine is totally safe for use up until a month past their original expiration date.’ ”
It’s not like something magical happens at midnight tomorrow,
Dr. Lynora Saxinger
This isn’t milk or yogurt, others added. “Vaccine lots are coded, with a ‘changeable’ expiry date because they keep and quality test lot samples for stability,” University of Alberta infectious disease specialist Dr. Lynora Saxinger said on Twitter.
“Summary: not a worry,” Saxinger said.
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In an interview, Saxinger said the World Health Organization’s position appears to say “don’t try to game the system by hanging on to post-expired vaccines, because that could lead to problems, especially in countries where there’s really short supply and maybe corruption and a lot more chaos.”
On the other hand, “if the extended stability data is available before the expiry date, you can update it. So, I actually think that’s fine. It’s not like something magical happens at midnight tomorrow,” she said.
The doses set to expire were small, relatively speaking (Ontario received a shipment of 254,500 AstraZeneca doses the week of May 17). But the extended shelf life comes as pressure mounts to accelerate second doses of COVID vaccines amid the growing threat of variants. Ontario’s COVID-19 science advisory table is warning Ontario Premier Doug Ford that the variant that first emerged in India, known as B.1.617, presents “a significant unknown.”
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It now accounts for about 150 to 200 new cases daily in Ontario, or 10 to 15 per cent of new confirmed infections in the province, with the bulk dominant in Peel, followed by “highly burdened” areas of Toronto, meaning areas with a higher burden of essential workers, lower socioeconomic status and crowded living conditions, said Dr. Peter Jüni, the table’s scientific director.
If this is an evidence-based decision ... then the key will be to frame the explanation in a way that is transparent
Timothy Caulfield
The group is now conducting modelling to determine how much could be gained in controlling the variant’s spread by moving fast with second vaccine doses in those areas. “What we want is for those regions that are now challenged with this new variant, we want full protection there so we can minimize the selective effect of partial vaccination,” Jüni said.
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In the meantime, people “should stay put where they are” and not travel between public health units, he said.
The variant, confirmed in most provinces, is believed 50 per cent more transmissible than the variant first identified in England, which was 50 per cent more transmissible than the early variants originally found in Wuhan, China. “This is basically upping the game,” Jüni said.
“We need to address this and not repeat the mistakes that were made in February — meaning, carefully monitor B.1.617 and, unlike February, react early if we see signals that it is getting out of control.”
A study published last week by Public Health England found that two doses of AstraZeneca vaccine were 60 per cent effective against B.1.617, while two doses of Pfizer-BioNTech gave 88 per cent protection against symptomatic disease.
However, both vaccines were only 33.5 per cent effective against the variant after one dose.
Additional reporting by The Canadian Press.
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Health Canada agrees to extend shelf-life of AstraZeneca as variant from India ups COVID threat - National Post
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