[jyl]

Well the AZN vaccine situation is getting more confusing. The half/full dose cohort was not planned, it was an *accident*. In the UK trial, some subjects accidentally got only a half dose at their first shot, this was discovered, and thereafter subsequent doses were the correct and intended full dose. This created a small (2700 approx) group of subjects who got half/full dosing.

AZN says the error was reported to the UK regulator and calls it a serendipitous error that allowed them to discover the supposedly higher efficacy of the half/full dosing. That spin is getting heavily criticized, along with the other weirdnesses that I mentioned in the prior post. I’m not sure how all this will affect the vaccine’s review by the FDA. AZN is disclosing information piecemeal, some publicly, some in private to investors, and the full dataset is presumably yet to be received by the FDA.

Best guess is: this is probably going to be considered a 62% efficacious vaccine, the “90%” efficacy claim for the accidental half/full dose regimen won’t be given much credence until/unless actually confirmed by a large trial, and while the AZN vaccine will probably get approved and used, PFE and MRNA are sitting rather pretty right now and the door has opened a little wider to JNJ NVAX and others. Likely not a big deal in the US which has contracted for enough PFE/MRNA vaccine to pretty much cover the vaccinable (is that a word?) population. Other countries will be reviewing their options.