Health Canada has issued a label change authorization for the Pfizer-BioNTech COVID-19 vaccine, allowing administrators to draw one more dose from each vial than previously advised.
That means that going forward Canadian health-care professionals who are giving the shots will be able to extract six rather than five doses per vial, an update from what was authorized when the vaccine was first given the green light in December 2020.
This comes after a scientific review done by the agency of data submitted by Pfizer, demonstrating that six doses could safely and accurately be extracted from each vial.
Health Canada’s concern, in part, was based on a requirement to have a certain amount of “overfill” in each vial to ensure that there is enough vaccine to sufficiently draw up the accurate amount to yield the expected doses. The regulator’s review found that an “acceptable” amount remains in the vials once six doses are extracted.
“In order to extract a sixth dose reliably and consistently, a specialized syringe should be used. A low dead-volume syringe is designed to have a lower volume of liquid that stays in the hub of the syringe after the vaccine is administered. This minimizes the loss of vaccine volume per vaccination,” said Health Canada Senior Medical Adviser Dr. Supriya Sharma at a briefing on Tuesday.
The government says that while this new guidance comes into effect immediately, this week’s shipments will remain calculated at five doses per vial, but going forward the shipment allocations across Canada will be altered to reflect that there are six doses contained within each vial sent.
Canada has a contract with Pfizer to receive 40 million doses of the vaccine, four million of which are to be delivered by the end of March. After weeks of shortages, next week’s shipment is expected to contain approximately 400,000 doses and 475,000 doses in the last week of February.
“While there is a change in doses contained in each vial, the country’s overall allotment from the manufacturer remains the same,” Maj.-Gen. Dany Fortin said Tuesday.
Fortin said that there are enough low-dead volume syringes in stock to continue Canada’s vaccine rollout under this new guidance, and more have been ordered.