TORONTO — Today, Dr. David Williams, Ontario’s Chief Medical Officer of Health, issued the following statement on the province’s first confirmed case of vaccine-induced immune thrombotic thrombocytopenia (VITT) in a patient after receiving the AstraZeneca/COVISHIELD vaccine:

“We have confirmed the first case of the rare blood clotting condition known as vaccine-induced immune thrombotic thrombocytopenia (VITT) in Ontario. The patient is a male in his 60s who had received his first dose of the AstraZeneca/COVISHIELD vaccine. The patient has received treatment and is recovering at home. Additional details will not be publicly released to protect the patient’s privacy.

The health and safety of Ontarians remains our top priority. While these serious reactions remain extremely rare, we have a robust process in place to monitor for any adverse events and have taken steps to ensure that these events are identified and treated as quickly as possible. All COVID-19 vaccines available in the province have been determined to be safe and effective by Health Canada, and have been shown to prevent serious illness, hospitalization and death.

This case marks the fourth case of VITT out of more than 1.1 million doses of the AstraZeneca/COVISHIELD vaccine that have been administered in Canada to date. We will continue to actively monitor the evolving situation and safety of all COVID-19 vaccines with our partners across the country.

Ontario will continue to offer the AstraZeneca vaccine to individuals aged 40 years and over at the time of vaccination or any time in 2021. This approach is helping to maximize the number of people protected as quickly as possible to prevent further transmission and the much higher risks that come from COVID-19 infection.

The Health Canada approved vaccines are the best way to protect your health and those around you. Ontarians are encouraged to get vaccinated as soon as they are eligible and monitor their health after receiving their vaccination.”