As of June 14, residents in Toronto, Peel Region, Porcupine, Halton Region, Waterloo, Wellington-Dufferin-Guelph and York Region will be eligible to book their second doses if they received their first dose before May 9.
Top doctors cite the increased hospitalizations and ICU admissions in the past week, a recent outbreak where there were a higher number of cases in a shorter period of time, and a slower drop in case counts despite vaccination rates as evidence.
Dr. Dirk Huyer, Ontario's chief coroner and another member of the province's vaccine task force, also defended the 12-week duration between doses, noting that the move is based "upon the data that's available". "We don't want to lose the gains that we have made in our province", Nazeem Muhajarine said.
"We believe that if we are able to really continue a high risk community focused vaccination strategy and do that really quickly and expeditiously we have a good chance of controlling the Delta variant and actually a really good chance at a good summer", he said. "To be clear, we're not out of the woods just yet".
Whether the timeline for the next phase changes will depend on what happens in the coming weeks, Elliott said.
"To avoid a fourth wave, we need to continue to ensure first and second doses in high-risk communities, continue tailoring vaccine clinics to community needs, and ensure strong testing and case and contact tracing", the COVID-19 projections state.
Dr. Anna Banerji, an infectious diseases specialist at St. Michael's Hospital in Toronto, said that even if someone is taking AstraZeneca for both their doses, the urgency of protecting people against the delta variant is the more important consideration at this point in the pandemic.
And ICU capacity is expected below 200 by next month, it's now at 450.
Those in hot-spot areas can book second shots through the provincial reservation system, public health units with their own systems, or at participating pharmacies.
Dr. Julie Emili, the associate medical officer of health in Waterloo Region, told council Wednesday evening that as new variants come in, they tend to be more transmissible. It would also support mobile and pop-up clinics. This would allow them to book second doses and receive an Ontario certificate of immunization.