KITCHENER -- The first doses of the Pfizer COVID-19 vaccine were expected to arrive in the Guelph area on Monday, but public health says that delivery date has been pushed back.

Officials had originally hoped to start limited vaccinations on Monday as well. The full vaccination program was scheduled to launch the following day.

But according to a news release issued on Monday, that's no longer going to be the case. Officials with Wellington-Dufferin-Guelph Public Health said that Pfizer informed them of the delay, later saying that the doses will now arrive by the end of the day on Wednesday and as late as Friday.

"This is obviously a disappointment,” said Dr. Nicola Mercer in a news release. “Public Health has been preparing to begin vaccinating our region against COVID-19 for months. While we can all recognize this is a complex logistical challenge, I share the frustration of everyone in the region at this delay."

Dr. Mercer adds that when they called Pfizer Monday morning for the exact time of arrival, they were told "very clearly it wasn't coming today." This led to the cancellation of 500 vaccination appointments for that day.

However, a representative from Pfizer says the information WDG Public Health was given was incorrect or not clear.

"Pfizer did not provide this update to the health region and there are no delays expected in our shipments," a Pfizer Canada representative said in a statement.  "It appears that their information came from the Ontario Ministry of Health, which shared that their shipments were expected in the week of January 4, 2021, but no specific dates were provided.”

Once the doses do arrive, they will be administered at the WDG Public Health office due to transportation and storage requirements, officials said.

“This is a major moment for our region,” Dr. Mercer had said in an earlier news release. “I know all of us have been anxiously waiting for this news and I am pleased to be able to share it with you. Receiving our first shipment of COVID-19 vaccine marks the beginning of the final phase of this pandemic, as we move toward providing a vaccine for everyone who wants it.”

Dr. Mercer acknowledges the difficult logistical challenge of rolling out a vaccine in such high demand that needs to be kept in such cold temperatures, but adds that they need arrival times in order to properly plan clinics.

VACCINE PLAN GOING FORWARD

Dr. Mercer had said the region will get shipments every Monday for the next three weeks. It's not clear whether or not that will still be the case. The first week was supposed to include 975 doses. They expect to receive 4,800 doses by the end of January.

The first vaccinations will be given to staff at long-term care and retirement homes, along with essential caregivers at those settings. High-risk health-care workers will receive the vaccine as more stock arrives in the region.

"This is the time for patience," Dr. Mercer said in her earlier release. "It will take several months before the vaccine is available to all of us who want it. In the meantime, we must all continue to follow the public health measures we know will keep everyone safe: gathering with only those you live with, wearing a face covering, maintaining physical distancing of six feet and practicing good hand hygiene. We want to make sure everyone gets safely to the end of this pandemic together.”

A Cambridge company is developing a special cold storage bag to transport doses of the vaccine while maintaining proper temperature.

"It's equipped with the sensors that communicate with wireless technology that ensures that whatever temperature that vaccine needs to be kept at, that the bag stays at that temperature," said David Meila with Bluerover.

Meila hopes the technology will help bring vaccines to those who can't access the vaccination hubs.

"The sheer number of people that we need to vaccinate in a short period of time and many of those are at-risk communities, whether that be in the north, in the Indigenous villages and communities or long-term health facilities," he said.

The newly approved Moderna arrived in Ontario on Wednesday and they'll be delivered to COVID-19 hotspots.

There's no word yet on when those vaccines will be distributed in Waterloo Region or Wellington-Dufferin-Guelph.

With files from CTV News Kitchener's Stephanie Villella, Krista Sharpe, and Tegan Versolatto