As Prime Minister Justin Trudeau and Sophie Grégoire Trudeau received their first doses of the AstraZeneca vaccine today, Canada has lowered the recommended age for the U.S.–made vaccine.

Canada's National Advisory Committee on Immunization (NACI) is now recommending the AstraZeneca vaccine be given to people age 30 and up “if the individual does not wish to wait for an mRNA vaccine and the benefits outweigh the risk,” according to updated guidance.

NACI previously advised that AstraZeneca be given to people age 55 and up after reports of rare blood clots following vaccination in Europe. Canada has since confirmed four cases of blood clotting in people who have received the shot.

After conducting a safety assessment, Health Canada said on April 14 that the benefits of the AstraZeneca COVID-19 vaccine outweigh the risks and adjusted the vaccine’s labeling with the latest scientific data.

“NACI recognizes that public health benefit-risk analyses for the use of the AstraZeneca COVID-19 vaccine may vary between jurisdictions based on factors such as local COVID-19 epidemiology; local vaccine supply and logistics; and equity and acceptability considerations,” the panel said in its new guidance. “These factors will change over time.”

The panel’s new guidance is informed by the chances of developing and dying from the rare blood clot condition compared to COVID-19 ICU admissions and deaths that could be prevented by an early dose. It also considered Canada’s rapidly changing epidemiology, including the circulation of variants of concern and hot spot areas, as well as “a comprehensive analysis of ethics, equity, feasibility and accessibility.”

Ontario's first case of AstraZeneca-related blood clotting

Today, Ontario’s top doctor confirmed the province’s first case of AstraZeneca-related blood clotting.

The condition, known as vaccine-induced immune thrombotic thrombocytopenia (VITT), is considered extremely rare.

“The patient is a male in his 60s who had received his first dose of the AstraZeneca/COVISHIELD vaccine,” Ontario's chief medical health officer David Williams said in a statement on this morning. “The patient has received treatment and is recovering at home. Additional details will not be publicly released to protect the patient’s privacy.”

This is the fourth case of VITT out of more than 1.1 million doses of the AstraZeneca/COVISHIELD vaccine administered in Canada to date.

Based on evidence, Williams says the vaccine’s benefits—preventing serious illness, hospitalization, and death—outweigh the risks.

Health Canada reported the first case of rare blood clotting related to the AstraZeneca vaccine on April 13. The federal regulator has said all vaccines approved for use in the country are safe and effective.

Ontario recently lowered the age of eligibility for AstraZeneca to 40 in a bid to ramp up vaccinations as COVID-19 cases and hospitalizations rise to record highs during the third wave.

“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,” Williams said.