How countries including Canada are trying to squeeze more COVID-19 vaccine from Pfizer-BioNTech vials

To get the extra dose from the Pfizer-BioNTech vials requires the use of a low-dead-volume syringe, which is not as common and is now in high demand.

To get a sixth dose out, a different syringe is needed. It’s become a hot commodity

A pharmacist fills a low-dead-volume syringe with the Pfizer-BioNTech COVID-19 vaccine at a vaccination site in New York on Jan. 26. The smaller syringe is required to obtain a sixth dose from the Pfizer-BioNTech vials. (Mary Altaffer/The Associated Press)

It was U.S. medical professionals who first discovered in December that they could get six doses — as opposed to five — from each vial of Pfizer-BioNTech COVID-19 vaccine by using special syringes that trap less vaccine around the needle after an injection.

The discovery was initially heralded as a way to stretch the precious vaccine even further.

Then the company stepped in to note its contracts are for doses, not vials: If a recipient can get six doses instead of five, then Pfizer-BioNTech can ship fewer vials and still fulfil their contractual obligation.

Deputy chief public health officer Dr. Howard Njoo says Health Canada is still reviewing the request to formally change the label to reflect that it contains six doses and is examining whether that sixth dose can be extracted consistently.

The problem is, the type of syringes needed to get six doses from the vial are in short supply.

WATCH | Understanding the issue of 5 vs. 6 doses per Pfizer-BioNTech vial:

Health Canada considers Pfizer label change from 5 doses to 6

1 year ago
Duration 3:12
Pfizer and BioNTech will cut back on how many vials of COVID-19 vaccine they send Canada this year if the federal health regulator agrees to change the vaccine label to say every vial contains six doses instead of five.

Why does it matter? 

Getting the extra dose from the vial requires the use of a low-dead-volume syringe that leaves less room for vaccine to get trapped in the needle and syringe after the plunger is pushed in all the way.

Those syringes are not as common as the three- and five-millilitre syringes mostly used in Canada's vaccine campaign now, and the smaller ones have become the latest hot commodity of COVID-19.

Canada trying to procure more syringes

Because the low-dead-volume syringes are generally used less often than standard syringes, they are now in high demand around the world.

Public Services and Procurement Canada tendered contracts last year for 145 million syringes, 95 million of which were of the more common three- or five-millilitre varieties.

Arianne Reza, an associate deputy minister at Public Services and Procurement Canada, says Canada does have some existing supply of the special, low-dead-volume needles needed to extract six doses from vials of Pfizer-BioNTech's vaccine.

She says two million more will be arriving in Canada next week, part of a new order for 37.5 million of the syringes.

During a briefing Thursday, Dr. Deena Hinshaw, Alberta's chief medical officer of health, said right now, it's not possible to get six doses from every vial.

"This is due to many factors including the global shortage of the type of syringes that would be required to more consistently extract this sixth dose," she said.

Major-General Dany Fortin, head of Canada's vaccine delivery strategy, said Thursday there must be consistency across the country, that every province must get the syringes required.

"We have been using across the provinces and territories different instruments, different types of syringes and been able to extract the six doses," Fortin said during a briefing Thursday. "In other jurisdictions, we did not have the right equipment, just could not do this consistently.

"We're taking measures across the country to ensure that we are able to draw as much as possible from those vials."

WATCH | Federal officials on whether a variety of syringes could be used:

Consistent syringe supply crucial to get extra COVID-19 vaccine dose from vial

1 year ago
Duration 2:02
Federal officials discuss why a consistent supply of the so-called low dead space syringe is necessary to extract a sixth dose of the Pfizer-BioNTech COVID-19 vaccine from each vial.

Will this affect Canada's COVID-19 vaccination goals?

European health officials have complained that a shortage of the special syringes needed is making it hard to get six doses out of each vial.

If Canada agrees to the Pfizer-BioNTech label change but can't get the six doses out of every single vial, its goal to vaccinate 20 million people with Pfizer-BioNTech's 40 million doses will be impossible to meet.

There have already been delays in getting the promised amount of Pfizer-BioNTech vaccine to Canada. Deliveries ground to a halt this week as a temporary shutdown at Pfizer's plant in Belgium disrupted its shipments.

A Belgian newspaper reported Thursday those upgrades are now complete, but a spokesperson for Pfizer confirmed Canada's deliveries won't return to a more normal level until next month.

"We expect the supply constraints of the Pfizer-BioNTech COVID-19 vaccine to last in Canada until mid-February when we will be able to increase allocations to catch up," the spokesperson said.

Syringe and vial of Pfizer-BioNTech vaccine in Halifax. Health Canada is reviewing a request to formally change the label to reflect that it contains six doses. (Robert Short/CBC)

Add to that, the European Union is threatening protectionist measures to limit the export abroad of doses produced in Europe.

"That will be very disturbing, of course," Prime Minister Justin Trudeau said earlier this week in French. "We are communicating with our partners in Europe to make sure the contracts signed by Canada are respected."

With files from CBC News


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.

Become a CBC Member

Join the conversation  Create account

Already have an account?