Vials of the AstraZeneca (L) and Moderna Covid-19 vaccines are pictured at the pharmacy of the Sant'Andrea hospital in Vercelli, Piedmont, Italy. AFP
Vials of the AstraZeneca (L) and Moderna Covid-19 vaccines are pictured at the pharmacy of the Sant'Andrea hospital in Vercelli, Piedmont, Italy. AFP

Canada's health authority says benefits of AstraZeneca vaccine 'far outweigh risks'