TORONTO -- Toronto is partnering with the TTC and Metrolinx to offer free rides to and from vaccination clinics this Sunday.

The TTC will require proof of appointment to access the service and riders will need to retain confirmation of their vaccination for a return ticket.

Vaccination clinic workers are also eligible for the free rides and will need to show employee identification for admission.

Meanwhile, Metrolinx says GO Transit and UP Express customers will be offered free travel to Union Station and Scotiabank Arena’s vaccination clinic and back again for anyone with confirmation of an appointment.

Staff and volunteers supporting the clinic can use the service as well with proper identification.

The initiative comes as the city announced Wednesday that more than 21,000 people have now booked a vaccination appointment at Scotiabank’s pop-up site. The event, dubbed “Our Winning Shot,” aims to break the Canadian record for most people vaccinated at a one-day clinic. The city said it hopes to vaccinate 25,000 people in total.

Ontario expanded second-vaccine eligibility in hot spots for the Delta variant on Wednesday, meaning some 546,147 additional people can now book their accelerated second dose at the Scotiabank clinic and other city-run immunization clinics through the provincial booking system.

As of today, more than 30 per cent of Toronto's eligible population have received a second dose of COVID-19 vaccine and are considered fully vaccinated, the city said.

In total, 3,001,002 needles have gone into arms throughout the city’s seven-month vaccination campaign, including first and second doses.