Gone are the days of administering COVID-19 vaccines to thousands of people in a single day at Toronto hockey arenas and convention centres.

With more than 90 per cent of people over the age of 12 now immunized, the city is shifting to a hyper-local approach targeting the city's ever-shrinking unvaccinated population.

"Building-to-building, door-to-door, because that's what's needed," said Shiran Isaacksz, vice president of the University Health Network and co-lead of the City of Toronto's Community Vaccination Table.

The most vaccine doses delivered on a single day in Toronto — 63,552 — happened on June 27, according to City of Toronto data. The city says 26,771 of those doses were administered at a single event at Scotiabank Arena, where residents got their shots in a party-like atmosphere with DJs playing music and pro hockey players raffling off Maple Leafs and Raptors tickets. But these days, vaccine clinics are small, specific and sometimes are serving as few as five people.

"It isn't the large clinics. It's much more about getting closer to the neighbourhoods and residents that need it, and creating that hyper-local access," Isaacksz told CBC News.

Isaacksz says the campaign is now much more community-based, as health-care teams are using Toronto Public Health data to determine what parts of the city have lower vaccination rates than the general population.

"So what we do is really work with the community leaders and the community ambassadors in any particular part of the city to understand where there might be a demand or need, Isaackz said.

"So it's really, I would say, a partnership with members of the community across the city."

Local pop-up vaccine clinics are being held at schools, community centres and Toronto Community Housing apartment buildings, among other locations.

Small-scale vaccination efforts have been happening throughout the vaccine campaign, but with mass vaccination clinics closing, more resources are being freed up for more local and targeted initiatives.

Dr. Marc Dagher, a physician and medical director at Women's College Hospital, says his team developed a model they call "mobile on mobile." It involves one or two members of a mobile vaccination clinic leaving the site to immunize a small number of residents who can't get there.

"We developed some certain approaches where we really figured out a way to send the smallest, or minimum team possible. We don't want to waste resources. So we're trying to be very adaptable," Dagher said in an interview.

His team also uses community ambassadors to connect with residents.

"These are very small, targeted, intimate clinics, if you want to call them that. And the purpose is to build trust," Dagher said.

Setting up a clinic and administering doses is only part of the effort. At this late stage, most people who enthusiastically embrace vaccines have had their shots. Health-care workers are now trying to reach those who are hesitant or just not motivated.

The VaxFacts Clinic at the Scarborough Health Network is a hotline where residents can consult with a doctor one-on-one to answer any questions about COVID-19 vaccines. It's available in more than 200 languages. Members of the Black community can request to speak with a Black physician.

"The mistrust in the health-care system is significant, and that's why we're able to step in and we have BIPOC physicians at the clinic who represent our population in Scarborough," said Dr. Latif Murji, the physician lead at VaxFacts.

"That goes a long way of building trust. And then on top of that, having a specific stream for the Black community to speak with black physicians is another additional step that we're taking to build that trust and have really positive conversations about vaccination."