TORONTO -- Ontarians aged 75 and older can start scheduling COVID-19 vaccine appointments through the province's booking portal on Monday.

Adults 75 and older were set to become eligible by the first week of April but Premier Doug Ford says the province's immunization effort is ahead of schedule.

"Thanks to the efforts of an army of frontline health-care heroes and volunteers, we are getting needles in arms even faster than we had imagined," Ford said.

The province said more than 50 per cent of Ontario residents aged 80 and older have now received at least one vaccine dose.

A pilot program offering vaccines in some pharmacies is also expanding and, as of Monday, will offer the Oxford-AstraZeneca shot to anyone aged 60 and older.

The pharmacy project previously only offered the shot to those aged 60 to 64 but the government says it is expanding after new guidelines deemed the shot safe for those 65 and older.

The number of participating pharmacies is also doubling to approximately 700 over the next two weeks. The province said that number is expected to rise to approximately 1,500 by the end of April.

Depending on vaccine supply, the province said retail pharmacies could administer up to 40 per cent of all vaccinations by the end of April.

Eligible residents can contact a participating pharmacy directly to make an appointment.