Ontario plans to eventually offer booster doses of COVID-19 vaccines to all residents, with the next priority group able to book appointments starting Saturday based on a higher risk of waning immunity. There are 2.75 million people who will become eligible for boosters starting Nov. 6 – those aged 70 and older, health-care workers and essential caregivers in congregate settings, people who received two doses of the AstraZeneca vaccine or one dose of Janssen, and First Nations, Inuit and Metis adults and their non-Indigenous household members.