A man in his 40s is believed to be the first person in Ontario to die after receiving the AstraZeneca vaccine and developing symptoms of a rare blood clot disorder.

The province's Associate Medical Officer of Health Dr. Barbara Yaffe confirmed the death during a press conference on Tuesday afternoon, noting that the man had recieved his first dose of the vaccine sometime in late April.

This marks the first death in Ontario related to a potential side effect of the AstraZeneca COVID-19 vaccine called Vaccine-Induced Thrombotic Thrombocytopenia or VITT.

VITT is incredibly rare according to health professionals, occuring at a rate of between 1 case per 26,000 to 1 case per 127,000 doses of AstraZeneca globally. To date, Ontario has administered approximately 850,000 doses of this particular vaccine.

The provincial government nonetheless paused its administration of the AstraZeneca/COVIDSHIELD vaccine two weeks ago as concerns mounted over increasing reports of the disorder in Canada and abroad.

There have been at least 16 reported cases of VITT blood clots recorded in Ontario to date, and at least four deaths nationwide linked to the rare side effect. More than 2 million doses of AstraZeneca have been administered in Canada.

People over the age of 40 had been rushing out to pharmacies for the AZ vaccine since Ontario first opened it up to their age group on April 20 and some who've received the shot are concerned, leading to an uptick in Google searches for "AstraZeneca blood clot symptoms."

Ontario's COVID-19 science advisory table has a full list of things to watch out for between days 4 and 28 after recieving your shot.

The province announced last week that, while it would no longer be giving out new AstraZeneca vaccines, people who'd already had a first dose would be able to receive the second.

It is not yet clear if this recent death in Ontario will impact the government's plans to offer second doses of the vaccine to residents, though it's of note that researchers say VITT side effects are much more common among people receiving their first shot than those receiving their second.