CTV News - Ontario expands booster eligibility

"Right now when we look at our older population in Canada, 94% have received at least two doses but only about 80% have actually received their three doses. So we need to do a much better job of getting that third dose to those that haven't gotten it yet before we start thinking about fourth doses. However, for those who have gotten their third dose and it has been over six months, this is where we recommend getting a fourth dose, to provide them with added protection," says Dr. Samir Sinha, NIA Director of Health Policy Research.