Ontario’s health minister says her government has been informed that Canada may receive about a half a million fewer doses of Pfizer’s COVID-19 vaccine than what was promised in the first quarter of the year.

Speaking at a news conference on Thursday, Health Minister Christine Elliott said Canada had initially expected to receive four million doses of the Pfizer vaccine by the end of February or the first part of March.

“We’ve now been told that's more like about 3.5 million so we are short about half a million doses,” Elliott said. “However, we are going to continue with our program. It is not going to affect what we are going to do. We are going to continue to support our most vulnerable.”

As part of the first phase of its vaccination program, the province promised to inoculate long-term care residents, workers, their essential caregivers, and frontline hospital workers, but vaccine shortages have now forced the Ford government to focus on providing first doses exclusively to long-term care home residents as well as high-risk retirement and First Nation elder care home residents.

During an update on Thursday morning, Maj.-Gen. Dany Fortin, who is overseeing the distribution of COVID-19 vaccines in Canada, said Canada will receive 4 million doses of the Pfizer vaccine by the end of March.

It appears Pfizer is planning to scale back its shipments to Canada under the assumption that each vial contains six doses of the vaccine. Initially the vials were thought to contain just five doses but some hospitals and vaccination sites have discovered that a sixth dose can be extracted from the vials using a special syringe. Canada currently has some existing supply of the syringes but 37.5 million more have been ordered and are expected to arrive starting Feb. 4.

While only the Pfizer and Moderna vaccines are currently approved for use in the country, Elliott, Premier Doug Ford, and Ret. Gen. Rick Hillier, the head of Ontario's COVID-19 vaccine task force, urged Health Canada to speed up approvals for other vaccines that have been rubber-stamped in other countries.

"We need to explore every avenue possible, no matter if it is asking Health Canada to speed up the approvals on the... Johnson and Johnson vaccine or the AstraZeneca. We need the approval as quickly as possible. Pfizer has let us down tremendously," Ford said on Thursday.

“Health Canada please. We need your help. Please approve these. These have been approved other places around the world."

The news of further potential vaccine shortages comes as Ontario's Ministry of Health revised downward the number of people who had received both doses of an approved coronavirus vaccine on Thursday, blaming a misinterpretation of data that appears to have been going on for weeks.

Instead of the 96,000 vaccinations reported to be finished on Wednesday night, officials said Thursday only about 48,000 had actually been completed at that point.

On Thursday, officials said 55,286 people had completed the two doses coronavirus vaccine regimen.

Infectious disease specialist Dr. Abdu Sharkawy said the revelation is troubling on multiple fronts.

“Even with the numbers that were originally posted, we were still well behind where we wanted to be.”

He said the new number indicates the vaccination program is going to take longer than originally thought.

“This is going to be a sore point with many and it’s going to create some difficulty in terms of people wanting and having to remain patient for an even longer period of time.”

A ministry spokesperson said the province had been mistakenly reporting the number of vaccines used to complete full inoculations, rather than the number of people actually receiving the full course of vaccination, as both the Moderna and Pfizer-BioNTech vaccines require two doses 21-28 days apart.

More than 317,000 vaccine doses have been administered since Dec. 15.

-With files from The Canadian Press