After an independent regulatory review, Health Canada has agreed with a request from Pfizer to recognize that each vial of the company’s vaccine includes six doses, not five.
The labelling change means that more shots can be squeezed out of each vial — and the company can ship fewer vials and still meet its contractual obligations to send a certain number of doses to its customers.
While some provinces — notably Saskatchewan and Quebec — have succeeded in extracting more from each vial, Health Canada had been saying up to now that the vials are only good for five doses.
Health Canada and other international regulators require vials to include a certain amount of overfill to ensure there is sufficient vaccine in each vial to yield the expected doses.
In its review, the regulator concluded that six full doses can be obtained consistently from the Pfizer vials through the use of low-dead-volume syringes, which allow the user to push virtually all fluid out of the syringe chamber. The government has scrambled to order large numbers of these syringes in recent weeks.
“In order to extract a sixth dose reliably and consistently, a specialized syringe should be used,” said Dr. Supriya Sharma, Health Canada’s chief medical adviser.
Public Services and Procurement Minister Anita Anand has said the federal government has ordered 64 million specialized syringes. One million were set to be delivered this week.
Change follows similar move in U.S. and Europe
Health Canada’s move follows a similar label change by the European Medicines Agency and the U.S. Food and Drug Administration (FDA) late last year.
According to health officials, each Pfizer vial contains 0.25 mL of product, to which saline is added as a diluting agent to obtain 2.25 mL of vaccine solution.
Each patient receives a 0.30 mL dose when they get a shot. That means there is enough product in a vial to comfortably cover six shots and still have a “buffer,” and to account for possible wastage.
Sharma said there have been anecdotal reports of some jurisdictions squeezing a seventh shot from these vials.
While the label change comes into effect immediately, shipments to Canada for this week that have already begun are calculated at five doses per vial. Canada is expected to take delivery of 70,000 doses this week.
The new designation means fewer vials could be shipped in the weeks ahead while the number of extractable doses remains the same, as long as provinces are properly equipped with the syringes. Under its contract, Canada has ordered a certain number of doses from Pfizer — not vials.
“While there is a change in doses contained in each vial, the country’s overall allotment from the manufacturer remains the same,” said Maj.-Gen Dany Fortin, the military commander leading vaccine logistics at the Public Health Agency of Canada.
“The distribution process though will not change, and vaccines will continue to be allocated on the basis of an equitable allocation framework that has been agreed to by all jurisdictions moving forward.”
Conservative Leader Erin O’Toole said Tuesday he fears the policy shift will let Pfizer get away with sending fewer shots than promised.
Some provinces have said extracting that sixth dose is often difficult — a problem the federal government insists will be fixed with the new syringes.
“The Liberals must also be clear with Canadians about whether Pfizer will replace any lost doses if the provinces are unable to extract the sixth dose,” O’Toole said.
Arianne Reza, a top bureaucrat at Public Services, told reporters Tuesday that the government will “monitor the situation” and work with Pfizer if there are any reports of missed doses as a result of the new standard.
O’Toole also said he worries the labelling change could disrupt an already shaky vaccine rollout by forcing health care workers to “retrain and change tack in the middle of a pandemic.”
Dr. Howard Njoo, Canada’s deputy chief public health officer, said the federal government will launch a series of “webinars” in the coming days to train health care professionals on how to use the new syringes.
“I think the real live issue right now is to ensure our provinces and territories can reliably and consistently get six doses out of each vial,” he said.
As part of this label change authorization, Pfizer is required to provide continued educational support to vaccine administration sites in Canada and to help the government to acquire more of the specialized syringes, if required.
After weeks of smaller-than-expected shipments because of production delays, Fortin said Pfizer is prepared to significantly ramp up shipments in coming weeks as it looks to meet its promised goal of delivering four million doses by the end of March.
“Starting on the 15th, we are expecting hundreds of thousands more doses each week — and that’s just from Pfizer,” Prime Minister Justin Trudeau said. “Moving forward, we’ll get more doses and get them even faster.”
Fortin said Canada is on track to receive and distribute approximately 400,000 doses next week and 475,000 doses in the last week of February — significantly more than what the company has delivered in recent weeks.
Canada falls to 37th worldwide for vaccines administered
According to the University of Oxford-based Our World in Data, Canada now ranks 37th globally in terms of vaccines administered — well behind allies like the United States and the United Kingdom and some middle-income countries like Turkey and Serbia.
Canada’s vaccination effort has also been outpaced so far by those in Bahrain, Denmark, Germany, Israel, Italy, Malta, Poland, Portugal, Romania, Slovenia, Spain and the United Arab Emirates, among others.
Health Canada regulators are expected to approve another promising vaccine candidate soon — AstraZeneca’s product — which could give a jolt to Canada’s sluggish vaccination campaign.
Sharma said the product is in the “final stages” of the rolling review process but department officials still need more information from the company before they can give the green light.
“It does take some time. There’s always some back-and-forth with the company at the end before we finalize the review,” she said. “We’re just waiting for the company to get back to us … to finalize the terms of the labelling.”
Sharma said concerns about the drug’s efficacy against new COVID-19 variants will be incorporated into the department’s review. On Monday, South Africa halted the rollout of the AstraZeneca product after it proved ineffective against the dominant strain of COVID-19 in that country.
Trudeau said the government is gearing up to vaccinate more people faster to prevent these new variants from gaining a toehold here.
As some provinces begin to relax restrictions and ease lockdowns, Trudeau said Canadians must remain vigilant.
“I think we’re all worried about the arrival of new variants and the impact that could have,” he said.