Earlier quoted context omitted.
As soon as the EUAs were issued, the vaccine manufacturers shut down clinical trial followup and, in many cases, allowed vaccination of the control branch of the trials. Same for Paxlovid, where support for independent trials was refused.
'allowed vaccination of the control branch' People in the control branch were told they were controls so that they had the option to get the newly-authorized vaccine for real. Standard practice for trials that go well.
I think it's standard practice for therapeutics, but not for vaccines?