Pfizer wants Health Canada to change the label on its COVID-19 vaccine, to show that each vial contains six doses instead of five.
It would mean the company, which has already delayed shipments to Canada, could send fewer vials.
A company spokesperson tells the Globe and Mail that pulling a sixth dose, "can help minimize vaccine wastage and enable the most efficient use of the vaccine."
Healthcare workers have sometimes been able to get six doses out of a vial but not consistently.
Pfizer says it can be done reliably with a specialized syringe. However those syringes are in short supply.
The U.S. and Europe have both agreed to the change.