The phone calls were (are) made to the participants (not by the participants which would have been worse) - & yes it does very much raise issues about the claims. This may be why the US members of the panel that approved Pfizer today were split 17 for & 4 against.So if Pfizer & Moderna were relying on phone calls from participants in the trial that surely would put into question how accurate the results are.
The AZ/Oxford trial the participant I know who was part of the trial was tested every Tuesday and was positive after one of them, guess they had the placebo.
AZ/Oxford get marks for doing actual physical weekly testing but lose many more from not being able to ensure they used the correct dosage. With AZ though it is not clear, from their filings, whether the weekly testing is solely for Phase 2 participants as their study is a combined Phase 2 & Phase 3 trial. Exactly how this is done is not clear in what filings I've seen so far.
That this dosage error was only picked up weeks later is the 'canary in the coalmine' potentially. How did they finally discover the error (which their media release does not call an error)? Since the results were so different 90% efficacy for a small number of particpants in 3 sub groups out of 60 vs 62% for the other 57 groups - they knew something was different. Just had to work backwards to try and work out what it was.
The issue with whether vaccinated people can still be spreaders is what I suspect will delay international borders being freed up. Does make you wonder why it was not tested in the first place doesn't it?