What you need to know about Ontario’s booster shots


More than 213,000 Ontarians have received a third dose of a COVID-19 vaccine so far as the province takes a phased approach to boosters, making them available first to people who are at higher risk of contracting the virus. Eligibility expanded to several new groups – about 2.75 million people – over the weekend. Here are answers to some key questions about Ontario’s booster shot program.

Are booster appointments readily available?

Public health units across the province are encouraging those eligible to book their boosters. But residents need to wait at least six months from when they had their second dose before getting a third shot, which means even those who currently fall under eligible cohorts may not be able to get their shots right away. Many booster appointments are going unfilled in some areas. The City of Toronto said it initially filled only 9,000 of 40,000 booster slots that opened over the weekend.

Why are boosters necessary?

Chief Medical Officer of Health Dr. Kieran Moore says evidence suggests immunity starts to wane six months after receiving the second dose of a COVID-19 vaccine. People who are older, have compromised immune systems or have higher exposure to COVID-19 are at the greatest risk, he said. But officials say for most people the waning immunity is not worrisome, as it’s their protection against mild illness that decreases, while they are still highly protected against severe illness and death.

Who can currently get a booster?

Those aged 70 and older, health-care workers and essential caregivers in congregate settings, people who received two doses of the AstraZeneca vaccine or one dose of Janssen, and First Nations, Inuit and Metis adults and their non-Indigenous household members are currently eligible for third doses in Ontario.

Transplant recipients, patients receiving treatment for blood cancers and long-term care residents are also eligible, as are recipients of anti-CD20 agents – a type of immunosuppressant.

What about other residents?

The province plans to expand booster shot eligibility to everyone aged 12 and older in early 2022, based on a six-to-eight month interval after people received their second doses.