Health Canada Says AstraZeneca Vaccine Safe, Effective but Will Add Warning on Clots

A vial of the AstraZeneca COVID-19 vaccine is seen with injection supplies at a clinic in Winnipeg, on March 19, 2021. John Woods / The Canadian Press

OTTAWA—Health Canada is devising a warning about a rare possible side-effect of blood clots from the Oxford-AstraZeneca vaccine but is still certain the inoculation is safe and effective against COVID-19.

The department’s chief medical adviser Dr. Supriya Sharma said Tuesday the plan for a warning comes on the heels of a similar move in Europe last week but doesn’t change Health Canada’s analysis that the vaccine’s benefits outweigh its risks.