What does the science say about AstraZeneca? A blood clot expert weighs in
TORONTO -- There's a new bump in the road to mass vaccination against COVID-19 in Canada.
Ontario, Alberta and Saskatchewan announced on Tuesday that they will no longer administer first doses of the AstraZeneca vaccine. Reasons cited for this abrupt shift include claims of uncertain supply and worries about the rare risk of blood clots from the vaccine.
However, authorities in other provinces have said that they do not plan to pause AstraZeneca inoculations, and federal health officials say they still consider the vaccine safe to use in most populations.
To help Canadians understand what the science says about the AstraZeneca vaccine, CTV's Chief News Anchor and Senior Editor Lisa LaFlamme spoke with Dr. Menaka Pai of McMaster University in Hamilton, Ont. Pai is an associate professor of hematology and thromboembolism – a blood clot expert, in other words – and a member of Ontario's COVID-19 Science Advisory Table.
Below is a transcript of the interview, edited for length and clarity.
Lisa LaFlamme: Doctor, you are on the Ontario Science Advisory Table, so your job is to look at the science. What triggered this sudden announcement today?
Dr. Menaka Pai: Well, it was the the science, Lisa. It's changing very fast, and the realities of the pandemic are changing in many parts of the country as well, and I think that this was a thoughtful decision based on evolving science.
LaFlamme: OK, so why was AstraZeneca such a success in the UK, and seemingly riddled with problems in this country?
Pai: I think AstraZeneca remains a very effective vaccination against COVID-19. It reduces death and hospitalization and serious illness, and that's what we're seeing in the U.K. Here in Canada, things are a little bit different. We are certainly more aware of the adverse events, we're looking for them, and we have the benefit of having access in the last couple of weeks to a lot more vaccine choices.
LaFlamme: So that's a choice, then -- we have the luxury of putting it on pause, for the first dose. But what about the second dose? Anyone who got the AstraZeneca feels a bit like a guinea pig right now, or maybe even a yo-yo. With so many varying opinions, what should someone do for their second dose?
Pai: First I want to empathize with that feeling. Lots of people I love have gotten a first dose and are worried. For the second dose, we're waiting on more science, so we're hoping that there's a study coming out of the U.K. that will show that mixing and matching doses is safe and effective. We also believe that the risk of these clots might be slightly lower with the second dose, and as that science comes in, we're going to be looking at that to make good recommendations to help Canadians, to reassure them.
LaFlamme: We are all hanging on every word, doctor. We thank you so much for your insight tonight.
Pai: Thank you, Lisa.