More than 640,000 vials are expected to arrive after weeks of delays.
Dr. Howard Njoo said discussions are happening about whether Canada should delay second doses.
Trudeau says we're about to see a "big lift" in deliveries after delays.
It could be years before everyone who needs a COVID-19 vaccine gets one.
The company's next shipment will be short by over 50,000 doses.
Vaccine deliveries are getting bigger but provinces still need time to have enough doses.
Some residents were hesitant to get the vaccine after misinformation swirled online.
Every effort should be made to follow those dosing schedules, but there can be exceptions, the National Advisory Committee on Immunization said.
The province expects its first shipment of the Moderna vaccine in the next 24 hours.
Meanwhile, Ontario and Quebec both reported record daily COVID-19 caseloads.