The rush to get initial doses of COVID-19 vaccines appears to be slowing down in the Prairies, with the rate of the eligible population getting a first shot hovering around 70 per cent in the three provinces.

Canada's chief public health officer, Dr. Theresa Tam, is warning that the country has to up its vaccination game, so efforts are being made to persuade more people to roll up their sleeves.

"We're seeing sort of a saturation of first doses ... and that is a concerning phenomenon that we need to address," Dr. Philippe Lagace-Wiens, a medical microbiologist at St. Boniface Hospital in Winnipeg, said in an interview this week.

Timothy Caulfield, a Canada Research Chair in health law and policy at the University of Alberta, is seeing the same trend in Alberta. He is optimistic the province can surpass 80 per cent "if we really try."

"It's going to be tough. It's going to require that we use every tool at our disposal," Caulfield said.

Lagace-Wiens and Caulfield say people who have not yet been vaccinated include outright pandemic deniers, people who are hesitant and those who face mobility, cultural or socio-economic barriers.

Recent data compiled by the Manitoba government has attempted to lay out the size of each group.

The data, a compilation of opinion surveys and online feedback first released in March, estimated 69 per cent of Manitobans were "keeners" intent on getting doses as soon as they could.

It said another 12 per cent were likely to get the vaccine but were not in a rush, about nine per cent were skeptical and undecided, and fewer than 10 per cent were adamant that they would not get a shot.

The government released updated data this month that estimated the number of keeners had risen while all other categories had dropped.

Governments are trying carrots more than sticks to win over the hesitant. Manitoba and Alberta are offering lotteries with prizes totalling millions of dollars. There are ad campaigns urging people to get a vaccine to protect their loved ones, or to help move a province to the point where it can reopen concert venues, theatres and large sporting events.

Saskatchewan Premier Scott Moe said this week his government will not hold a lottery.

"You get to protect your family, your friends, your loved ones and everyone around you from this COVID virus," Moe said Tuesday.

"If you like to gamble, then I would suggest to you don’t get your shot. The prize is not what you think."