TORONTO -- Ontario will limit the AstraZeneca vaccine to people under the age of 65 on the recommendations of the National Advisory Committee for Immunization (NACI), Ontario’s Health Minister confirmed, but the province is still finalizing the plan for who will be prioritized for that shot.

Christine Elliott also said the province is looking for guidance from the NACI on delaying the second dose of the COVID-19 vaccine by up to 16 weeks in an effort to dramatically expand the number of people receiving their initial inoculation, and suggested those recommendations will be the final key Ontario needs to unlock its plan.

“This could make a significant difference for Ontario in reducing hospitalizations and deaths,” Elliott told reporters at Queen’s Park. “As soon as we receive that [recommendation] we will be able to finalize the plan and get in front of you.”

The province is facing increasing pressure to reveal how it plans to vaccinate a broad segment of the population as it prepares to receive more than a hundred thousand doses of the AstraZeneca vaccine in the coming days.

The federal government announced 300,000 doses have been shipped from the Serum Institute of India -- putting Ontario’s per capita share at roughly 114,000 doses – all of which expire on Apr. 2.

“Right now, we're doing the calculation based on the AstraZeneca vaccine coming into the mix,” Elliott said. “This is something that we did after we got started with Pfizer and then we introduced Moderna. In the same way, we're building AstraZeneca into the plan as well.”

The quick expiration date raises questions about whether Ontario will be ready to administer the doses within the timeframe provided, given that the province’s portal to register patients for the vaccine will only be launched on Mar. 15.

Elliott told MPPs in the Ontario Legislature that the “big system” was soft-launched in select public health units on Monday because the government doesn’t want the portal to experience the type of crashes seen in Alberta and Quebec.

“We want it to be solid and to stand up to the pressure that we know is going to be coming because people are anxious to know when they’re going to be receiving the vaccine,” she said.

The NDP said the province is “unprepared” for the increased shipments of vaccines and said it was “obvious that they haven’t done their work.”

“We're literally days away from AstraZeneca arriving, why isn't the government being upfront, being clear, being transparent about what the plan is,” said NDP leader Andrea Horwath, who added that in the absence of a detailed plan, the government should have outlined the potential options that public health units could exercise.

While some of the government’s critics say the province should be cut some slack given the federal government’s ever-evolving vaccine rollout, they say it doesn’t excuse the province’s lack of clear direction.

“There's no question that this is not an easy endeavor, vaccinating 14 million people. That's why you need to plan, because then you can adapt quickly,” said Liberal MPP John Fraser.