A man in his 60s is the first Ontarian to suffer from blood clotting due to the AstraZeneca shot.
Ontario's Chief Medical Officer of Health Dr. David Williams confirmed the case, noting that out of over 1.1 million doses administered in Canada, four people have developed clots.
Williams went on to say that reactions such as this are rare, and it shouldn't stop people from getting vaccinated.
"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."
The patient, who had the reaction after getting his first dose, has received treatment, and is recovering at home.
Meanwhile, the province will continue to offer the AstraZeneca vaccine to people 40 and older.