The Oxford-AstraZeneca shot was heralded as a “game changer” in the global immunization strategy, Greenberg said in an email. It’s cheaper and easier to store and distribute than its rivals.
The latest controversy “presents an enormous challenge for vaccine risk communication,” he said, and some worry VIPIT — vaccine-induced prothrombotic immune thrombocytopenia — risks sowing another layer of doubt on fertile ground.
Canadians’ hesitancy toward COVID-19 vaccines had been softening in recent months. According to polling by the Angus Reid Institute, 66 per cent of 1,748 Canadians sampled in the first week of March said they would get a vaccine as soon as they’re eligible rather than take a wait-and-see-approach, up from 39 per cent in September. “The overall number of Canadians who say they will not be vaccinated,” the pollster reported, “remained stabled, at 12 per cent.”
However, “Being hesitant or undecided in the face of a possible safety risk is not being anti-vaccine,” Heidi Larson, director of The Vaccine Confidence Project at the London School of Hygiene & Tropical Medicine, and George Washington University associate professor David Broniatowski wrote in the journal Science. “A failure to understand the distinction can feed both fires.”
The approved COVID vaccines were each tested in tens of thousands of volunteers. However, rare side effects, rare “events,” might not be picked up until many millions receive it, said Dr. Theresa Tam, Canada’s chief public health officer.