I'm going to turn to something you've written about AstraZeneca on our website. You wrote:
Some have argued—as the Ontario government just acceded—that patients can receive informed consent regarding the risk of VITT prior to getting a second dose of AZ. They are basing this on rather preliminary UK data; the same UK data that has consistently underestimated the 1st-dose VITT risk (starting off with 1:600K, then 1:250K, and is now down to 1:81K). They started off with a 1:1M 2nd-dose VITT risk, and now are quoting 1:600K risk after 15 cases. I am fairly certain the likelihood of risk is higher than this, but the magnitude is entirely uncertain.
What advice do you have, Dr. Morris, for Canadians who have received a first shot of the AstraZeneca vaccine and will reach the end of their four-month dose interval before trial data is available on vaccine mixing?