Peel Region has joined a growing list of Ontario municipalities who are now vaccinating members of the general population over the age of 80 but the local medical officer of health is cautioning people to be patient as vaccine supply is still limited.

“At this point in time in Peel, most of our vaccines that are available for 80 plus are being delivered at our two hospital sites, both at William Osler in Brampton as well as at Trillium Health Partners in Mississauga. Both hospitals have systems up and running,” Dr. Lawrence Loh told CP24 on Tuesday.

“I understand of course with the volumes that there may be challenges in getting access to some of these limited appointments and really urge people if they can't get one now, please check again later. Continue to try.”

Loh said at least 1,500 appointments have already been booked at the William Osler site over the next few days.

“I want to really stress though, we are talking on a day-to-day basis, hundreds of appointments and we know we've got 55,000 seniors in our community,” he added.

“So it may take some time for us to make sure that we have all appointments available for that important age group while we also still continue our frontline health-care worker campaign as well.”

Other municipalities in the province began vaccinating the oldest members of their communities on Monday, including York Region, which booked all available appointments an hour-and-a-half after opening its vaccination program up to the public.

Online booking portals crashed at periods throughout the day due to the surge in activity.

“Right now we are limited by our supply and limited by the significant demand that is out there so we receive allocations from the provincial government on a weekly basis and we will certainly try to match those appointments to demand,” Loh said on Tuesday.

“As supply continues to increase, keep on checking back because more and more appointments will become available.”

Loh urged people to continue to follow public health measures to prevent further spread to those who have not yet received a vaccine.

“COVID is still transmitting in our community and we do need to be very cautious and a vaccine doesn't help you if you haven't got it yet,” he said.

“So sticking to the precautions, reopening gradually, that will give us a chance to get vaccine coverage up to offer people that protection and hopefully get back to some set of normalcy.”

He assured anyone weary of getting a vaccine that there is a significant body of evidence to indicate that they are safe.

“Ultimately when your turn comes to get the shot, this is our best chance essentially to exit from the pandemic and make sure we can go back to hugs, go back to the ordinary things we used to do as human beings,” Loh said. “Definitely when your turn comes, don't miss your shot.”

Ontario plans to officially roll out its vaccine appointment booking system provincewide on March 15 and the City of Toronto has confirmed that it will be waiting for that date before opening up appointments to the oldest members of the general public.

Officials say the city is still focusing on vaccinating other priority groups, including frontline health-care workers.

Last week, the Ford government provided a set of dates for when people over the age of 60 can expect to receive their first dose but recent developments could substantially speed up that timeline.

Initially, the province said people between the ages of 60 and 65 would have to wait until July 1 to receive their first dose but the approval of the AstraZeneca COVID-19 vaccine will likely mean Ontario will be able to administer vaccines to that age group a lot sooner than planned.

The Ontario government is also considering waiting longer to administer second doses or the Pfizer-BioNTech and Moderna COVID-19 vaccines, which would allow the province to provide first doses to significantly more members of the population in the coming months.

On Monday, British Columbia confirmed that it plans to extend the time between both doses to four months and hours after the announcement, Ontario’s health minister and solicitor general confirmed that the Ford government is now looking into the possibility of pushing back second doses here as well.

Discussions on dosing intervals are also underway at the federal level, Canada’s Deputy Chief Public Health Officer Dr. Howard Njoo told reporters on Monday.