HALIFAX -- Despite ongoing reassurances from health officials that Pfizer and Moderna vaccines are virtually identical and interchangeable, it seems many Canadians still prefer Pfizer and they're willing to wait to get it for a second shot -- but not necessarily in the Maritimes.

Moderna supplies have increased dramatically in recent weeks, prompting public health officers to urge residents to book second shots as soon as possible.

"I also want to reiterate that there is no difference between Moderna and Pfizer vaccines," said Nova Scotia's chief medical officer of health Dr. Robert Strang during opening remarks at a COVID-19 briefing in Halifax on Tuesday.

"They are both mRNA vaccines, and both very effective," Strang said.

The sentiment was echoed by New Brunswick's top doctor on Wednesday.

"Those who received a Pfizer-BioNTech product as their first shot can get a Moderna vaccine for their second," said Dr. Jennifer Russell in Fredericton.

"These vaccines work in exactly the same way and are equally effective, separately or in combination."

In Dartmouth, about a thousand Pfizer appointments were booked at a former retail site at the Mic Mac Mall on Wednesday.

Retired engineer Michael Monteith was among those who'd come to get a shot, but insisted he had no preference on which vaccine he got.

"I wouldn't care if it was Moderna, if they had that," the 80-year-old told CTV News.

"Or if they didn't have a Pfizer. I would take Moderna."

Reg Clarke from Lower Sackville agreed.

"It didn't matter to me. As long as I got one, because everybody says they're both the same," Clarke said.

Those on the front lines of distribution around here say there doesn't appear to be any particular preference, but Maritimers seem to seek the satisfaction of keeping both shots the same.

"It's been hesitancy in switching that vaccine. It's not hesitancy in one vaccine over the other," said Allison Bodnar, CEO of the Pharmacy Association of Nova Scotia.

"If we look at the bookings, every booking we have for the next few weeks is full, whether it's for Moderna or Pfizer, or quite frankly, the end of the AZ allotment," she added.

"I think in Atlantic Canada, people just want to get their second shot,"

Leaving the mass vaccine site in Dartmouth, Monteith offered advice for anyone hesitating to book based on manufacturer preference.

"Don't wait another month," he said. "The risk is too great."