Canada's expert panel on immunization didn't contact Pfizer before its recommendation that the second dose be delayed up to four months.

Pfizer Canada's president, Cole Pinnow, made that point today when he spoke to the House of Commons health committee.

The advice came from the National Advisory Committee on Immunization because real-world data on one dose shows it is highly effective and with limited supplies, more people could get vaccinated with one dose sooner.

Pinnow says one reason is that Pfizer believed the vaccine wouldn't get approved here until well after the New Year.

Cole Pinnow says when the company signed a purchase agreement last August, it didn't expect its vaccine to get approved here until February, but it was approved in December.

He says at that point Pfizer began moving quickly to deliver doses to Canada months earlier than planned. Pinnow says changes to the dosing schedule could make more Canadians vaccine hesitant and that a federal committee did not contact Pfizer before it changed the timing between doses from three weeks to four months.