Biffer wrote: Wed Nov 18, 2020 4:13 pm
Saint wrote: Wed Nov 18, 2020 2:50 pm
Raggs wrote: Wed Nov 18, 2020 1:59 pm
When is the AZ vaccine expected? It was one of the furthest ahead wasn't it, not heard much on it recently? That'll be the game changer for the UK you'd think.
Imminently is the word. All 3 entered Phase III at roughly the same stage, but I think Pfizer and Moderna may have recruited test subjects faster (also, AZ started in the UK when there wasn't much Covid around - the other 2 were in the US where they've had much higher amounts of Covid all the way through, so they were more likely to reach the threshold numbers for the trial faster).
Assuming AZ is succesful; it's a global game changer - significantly cheaper (around a 10th of the price), simpler logistics, etc.
The mRNA stuff though is the long term game-changer for all vaccine development, as well as potentially an answer to Cancer
You know more about this than me so - am I right in saying that trial length isn’t a certain amount of time, it’s determined by the number of infections in the trial group? And that’s why the AZ trial starting in the UK when rates were lower will take longer?
Basically, yes. I'm unsure about the exact criteria used to determine how many infections are needed (it's partly a function of the size of the trial group). but that's how it works - they need to get to x number of infections, at which point they un-blind the trial and see how many had the vaccine and how many the placebo. You can under certain circumstances un-blind early but it's risky - once un-blinded the trial is over, so if the numbers aren't definitive then you start from scratch and throw the data you've already got away. So AZ started in spring in the UK as numbers were rapidly tailing off, they added Brazil, India, Japan, South Africa and the US - but the US trials didn't start till August, and it's a double dose 4 weeks apart so even for the first US volunteers they're only a month or two into the immunity (also worth noting they had trouble restarting in the US after the hold due to an issue with presenting data to the FDA in the correct format). Also the scale for the AZ trial is huge - they have more participants in the US than Pfizer had globally for instance
There is some un-blinded work being done on the safety data with the AZ vaccine, where that's being independently analysed already, so as to short circuit the approval process assuming the trial is successful - but they don't have access to the actual success or otherwise of the vaccine, they're just analysing side effects, age groups etc