The University Health Network says it began communicating with staff about the policy in June and aims to have it fully implemented by August 9.
Staff must declare if they have been vaccinated against COVID-19, if they have medical exemption, if they have refused to share their status, or if they will not be vaccinated.
Employees who are not vaccinated, as well as those who will not share their status, will receive home COVID-19 tests to complete and report 48 hours before coming to work.
Spokeswoman Gillian Howard said between 85 and 90 percent of full-time staff are vaccinated.
She says the hospital network is taking longer to confirm that part-time and casual staff are aware of the requirement.