Ontario’s top doctor says students aged 12 to 17 who aren’t vaccinated against COVID-19 will be subject to stricter isolation rules in the event of virus outbreaks this fall.

Dr. Kieran Moore says students who are fully vaccinated against the virus will have to take COVID-19 tests if they’re in contact with a high-risk person.

Students who test negative can go back to school, but those who aren’t immunized will be off school for a minimum of 10 days while they wait for test results.

Moore says unvaccinated students will have to take a second COVID test after about seven days, and they could be out of class for up to 20 days depending on the result.

The province hasn’t yet released its complete back-to-school plan and Moore says the details about public health measures are still being finalized.

Sixty-four per cent of Ontario youth aged 12 to 17 have one dose of a COVID-19 vaccine and 42 per cent are fully vaccinated.

Moore called for parents to get their children vaccinated this week, noting that time has nearly run out for full immunization to kick if before school starts in September.

“There is an advantage, just alone … to being present in school, full participation in all sports and activities, by being immunized,” Moore told reporters on Tuesday.

“I hope that parents and students see that advantage.”

Moore said the province is working on a plan to vaccinate children aged five to 12 for when vaccines are approved for use in that age group — something he anticipates may happen by late fall or early in the winter, depending on when trials and approvals wrap up.

The fall plan for school may also include masking, Moore said, as public health monitors the virus situation.

Moore stopped short of supporting a vaccine mandate for students and school staff on Tuesday. He said he doesn’t think the policy is necessary at this point because immunization rates in the province are already reasonably high, with 79 per cent of eligible people having received one dose.

“I don’t think it’s a necessary tool in our tool kit just yet,” he said.

Premier Doug Ford has said he doesn’t support mandating vaccines for workers, leaving it up to employers to develop their own vaccination policies.