Testing vaccines in the time of Covid: The changing landscape.

The initial trials of SARS-CoV-2 vaccines were randomised control trials (RCT) with a placebo as control. The use of a placebo was ethically justified because, as with any new and emerging infectious disease, there was no known vaccine. There are now at least eight vaccines that have been shown to be effective and approved for emergency use, so the use of a placebo in the control group is no longer ethically justified. This article discusses why ethical guidelines should be continually evaluated in a changing landscape and why trust is so important.