[Nitramp]

Do you have a source for this?

Multiple people died over the course of the efficacy study for the BioNTech/Pfizer vaccine, and yet they completed the study: https://www.nejm.org/doi/full/10.1056/nejmoa2034577

In general, what you claim would seem both surprising and impractical to me. There are many studies on very seriously ill groups, where the death of a large portion of participants is expected.