TORONTO -- Ontarians will have the option to get their second dose of a COVID-19 vaccine sooner as the province moves to shorten the interval between shots.

The province says it's able to make the move because 65 per cent of all adults have at least one shot and Ontario now has a steady vaccine supply.

Ontario has been administering COVID-19 shots four months apart with some exceptions.

Shortening intervals between doses is part of the province's plan to fully vaccinate all willing adults by the end of the summer.

The province says the shortened interval could be as small as 28 days for the Pfizer-BioNTech and Moderna vaccines in the coming months, depending on supply.

Those who got a first shot of the Oxford-AstraZeneca vaccine will be offered a second dose after 12 weeks, though it could be a different vaccine depending on awaited federal guidance.

Moving up the second dose is optional and people will keep their original appointments if they don't re-book for an earlier shot.

Ontarians aged 80 and older can start booking their second doses next week, while those aged 70 and older will become eligible for second shots in the week of June 14.

After that, the province says residents will become eligible for second shots based on when they got their first dose.

Those between the ages of 12 and 25 will become eligible in early August.

The province is planning a push to vaccinate the majority of youth aged 12 to 17 next month, with their second doses set for August, so that as many youth as possible will be fully vaccinated by the start of the school year.

Vaccination teams also plan to start offering shots to youth in 31 fly-in First Nations communities and Moosonee in northern Ontario starting Monday.

The second-dose plan is based on confirmed vaccine shipments from Ottawa and provincial officials say it could move faster if supply increases.

Ontario reported 1,273 new cases of COVID-19 on Friday and 14 more deaths linked to the virus. The data is based on nearly 40,900 completed tests.

Health Minister Christine Elliott said there are 269 new cases in Toronto, 268 in Peel Region, and 101 in Ottawa.

The Ministry of Health says 1,023 people are in hospital -- 645 in intensive care and 458 on a ventilator.