RE: Human trials question?24 Jun 2020 19:20
My understanding is that these trials can take many years, as you are giving a vaccine (plus placebo) to a study population and then you wait and see if anybody catches Covid, it is a very lengthy and hard to control process, lots of variables involved, will the persons come in contact with the virus etc. With the challenge studies the study group have the vaccine (and placebo) and then they are deliberately infected with the virus, this would need strict control, hence permissions needed but you know for sure if your vaccine works?