So GSK and another pharma have initiated trials of the Ebola vaccine in Liberia. But how are they going to prove causation between administering the vaccine and protection from Ebola? Ethically it is not possible to forcibly expose the vaccine recipients to the virus, which means that any vaccine recipient who does not contract Ebola might have been protected by the vaccine, or might just have never encountered the virus - AFAICT the best that they can do is to present a very strong association.
Right. That's how most vaccines are evaluated. There are still areas where Ebola is active, and those areas will likely receive some of the earliest trials of the vaccine. If it works then it moves on to vaccination of healthcare workers (who are regularly exposed as part of their job) and they get a stronger correlation.
I wonder if pharma companies would actually intentionally plant a virus and initiate an outbreak in order to engineer the market demand for a treatment or vaccine - for profit's sake?