You're right, and researchers are aware of this: https://www.statnews.com/2020/09/03/placebos-arent-needed-challenge-trials-covid-19-vaccines/ https://www.stat

You're right, and researchers are aware of this: https://www.statnews.com/2020/09/03/placebos-arent-needed-challenge-trials-covid-19-vaccines/ https://www.statnews.com/2020/09/03/placebos-arent-needed-ch... Also, there is a very strong risk, given the global situation, that the longer placebo-controlled trials go on, the less reliable the data will be, because control-group subjects will ignore the rules of the study and go get vaccinated as soon as it's broadly available just in case. So even just looking at data quality and excluding other considerations, placebos have major risks that probably outweigh the benefits of administering them for months or years like a usual vaccine trial would.