Mass immunization clinics in which vaccinators and volunteers move around a circular set-up of chairs - with clients staying seated - was by far the most efficient model in an Ontario government study comparing different sites.

The Ministry of Health study, obtained by The Canadian Press through a freedom-of-information request, looked at nine different mass vaccination clinics in the last six months of 2021 with an eye to supporting possible future large-scale vaccine campaigns.

The traditional, drive-through and "circular hockey hub" models all had different strengths and limitations, but the circular hockey hub clinic was able to vaccinate the highest number of people per staff member, and clients spent the shortest amount of time there, the study found.

The hockey hub model sees the client sit in one chair and have staff and volunteers come by to complete registration, medical screening, vaccination and observation time all in the same place.

One graphic in the study breaks down the maximum number of doses per vaccinator per hour. The circular hockey hub model saw 50 doses per hour, while the traditional models achieved 13 doses per hour, and the drive-through site saw seven doses per hour.

As well, clients at the circular hockey hub clinic spent a total of five minutes from entrance to getting vaccinated, where the process took 11.5 minutes at the traditional clinic and nearly 14 minutes at the drive-through sites.

The circular hockey hub clinic was run by the Scarborough Health Network, and Dr. Amir JanMohamed, a cardiologist who helped design the model, said if they had to run a mass vaccination clinic again, he would definitely use it again.

"Hopefully we don't have another major outbreak (and) we need to do vaccines," he said in an interview.

"But if we are going to do things, then it behooves us - and this is a motto or modus operandi we have in Scarborough - is to innovate and be efficient and be responsible users of our resources."

JanMohamed said he looked at a non-circular hockey hub model that another hospital was using, with chairs arranged in lines and rows. There were inefficiencies, he said, in the vaccinators having to walk along a line of 15 chairs spaced six feet apart to get back to the start.

By making the model circular, it would be faster and less tiring for staff, JanMohamed said.

When the COVID-19 booster campaign was first rolling out, in December 2021 and January 2022, a natural experiment presented itself, he said. The hospital was planning a clinic at an Ismaili community centre and there were two spaces in which they could do vaccinations, one a traditional hall, the other a rotunda.

"We said, 'Can we put circular models in the rotunda and the square models in the in the social hall, and can you do head to head comparison?"' JanMohamed said.

"The best measure is a head-to-head comparison where there is no other changes except for the way (vaccinators and staff move) around."

In the rotunda, four teams delivered 653 vaccines, while in the hall five teams delivered 555 vaccines, he said.

"The proof of the pudding to me was watching people sit in the chairs after getting vaccinated, texting and tweeting to their friends and family to say, 'Hey guys, guess what, you can come here and I was in the chair in X number of minutes, and I'm leaving in 10 minutes. You want a vaccination? Come here now,"' JanMohamed said.

Drawbacks of the circular hockey hub model laid out by the government study include limited ways to accommodate people with physical or developmental disabilities and a higher physical burden on staff.

The drive-through models were able to reach people with accessibility challenges and make use of outdoor spaces when risk of transmission is high or there are no indoor spaces available, the study found. However, they can also be hard on staff, who are on their feet most of the time and exposed to the elements, it said.

Traditional vaccine clinics lessen the burden on staff, who are mostly able to sit and can be used in small or irregularly shaped spaces, but require "significant" client movement and have higher exposure to viruses due to the longer time spent indoors, the study said.

This report by The Canadian Press was first published Monday, March 6, 2023.