TORONTO -- More Ontarians will soon be able to book an appointment to receive a third dose of a COVID-19 vaccine as the province expands its eligibility for booster shots amid growing concerns over the Omicron variant.

On Wednesday, the Ontario government announced that anyone over the age of 18 in the province will be able to book their appointment starting at 8 a.m. on Dec. 20.

Premier Doug Ford also introduced a shortened interval between second and third doses. Ontario residents now can wait three months between getting a second and third dose of a COVID-19 vaccine.

As more Ontarians become eligible for booster shots, Ontario’s Chief Medical Officer of Health Dr. Kieren Moore said that discussions were underway in the province to potentially redefine what it means to be fully vaccinated – whether two doses or three doses qualifies.

“We certainly are encouraging all those that are eligible at present for the third dose to get theirs and we'll be following the immune protection of a third dose against Omicron to understand what immunologically represents the best protection. That may change the definition of what is fully immunized,” Moore said.

Moore says a robust third dose strategy is critical in Ontario given how fast the Omicron variant is spreading. A report issued Wednesday from Public Health Ontario suggests that the Omicron variant likely already accounts for more than 80 per cent of the COVID-19 cases being confirmed in the province each day. 


Residents can book their shot through the Ontario vaccine portal or by calling the Provincial Vaccine Contact Centre at 1-833-943-3900.

Bookings can also be made directly through public health units that use their own booking systems, through Indigenous-led vaccination clinics, select pharmacies, and primary care settings, according to the government.