This question has been inspired by current events, namely the Covid-19 pandemic and, ermm... let's graciously call them "vaccine skeptics". Also of note is that I'm not a medical scientist or even in any way connected to medicine, so my knowledge can be waaaay off.
I feel like I have a rough, general understanding of the process required to bring a new drug to market. You first come up with the substance, then you try it in a petri dish and/or animal models, then you gather evidence that it does no harm, then you gather evidence that it does bring benefits, and along the way you also gather data on the exact efficiency, side effects, etc.
Now, all this research is almost always done and funded by private pharmaceutical businesses. It's all very expensive so the companies are very interested in shining results of the tests so that they can sell lots of the new drug. This has on occasion lead to foul play, but I gather that most of the time these results are pretty trustworthy.
So my question is - what makes them trustworthy? I understand that the research gets both peer review and government oversight (so we have neutral and/or competing third parties looking over their shoulder), but how do you check that the reported results are actually the same as observed in the field? In general, what steps are taken to make cheating in this research difficult?
