Ontario is expected to detail its plan for fourth COVID-19 vaccine doses today.
Health Minister Christine Elliott says the province intends to offer fourth shots to people aged 60 and older.
Fourth doses are already available to long-term care and retirement home residents and immunocompromised people in Ontario.
Plans to expand second booster shots are expected after the National Advisory Committee on Immunization advised provinces and territories to prepare to roll out fourth shots in the coming weeks.
The committee is recommending provinces prioritize people aged 80 and older and long-term care residents, and strongly recommends fourth doses for people between the ages of 70 and 79.
NACI says it's still studying whether second booster shots are necessary for younger adults and adolescents.