You can't "do studies on them after". These aren't studies for the sake of publishing papers but to determine whether or not the drug is safe to use and whether it is actually effective.

If the drug or vaccine you are developing ends up killing more people than saving it is not much of a cure, is it?

The same if the drug isn't effective - in that case it would be wasting critical resources and probably causing the sick to not get a really effective treatment.

That said, this process will be certainly sped up to maximum amount possible, given the situation, but it will still take a long time.

You can. If you give it on a compassionate use basis to folks who are dying and if 50% more live vs. comparables then there's your study.