But this is probably known to people who are in the field. You have to defend your decisions the same way you would in business or investing, but instead of people shorting your stock, you will have people trying to cut your funding, accuse you of causing harm and ultimately trying to destroy your reputation/career.
It’s fascinating how this trap of group fallacy has the potential to affect different fields, like there’s some universality to the human behavior behind it.
In a sane world, the government's reopening plans aren't dictated by the local restaurant owners, but rather by health organizations run by scientists. In such a world, concerts won't happen again before it is actually safe to do so. Surprisingly, there are some places in the world where that is actually the case!
The question though, isn't if a particular drug is safe or not. That's a very important question to answer, and one of the hurdles to pass, but in this context, the ethics are around exposing people to a potentially fatal disease, without actually knowing if the vaccine being tested successfully protects against the disease. If we inject people with a vaccine, and then with large amounts of the SARS-Cov-2 virus, and they develop COVID-19, then we can say that the vaccine being tested on them didn't work in that case. Unfortunately we directly injected them with a potentially lethal disease, possibly resulting in a life-long disability.
It's that last step that most hospital ethics boards aren't willing to take.
In this case, it is different. People will put pressure on the government to allow concerts again rather sooner than later and the default case is probably that there will be concerts again before the Corona situation is over. If you don't do the test, you have to make the decision whether / when to allow concerts again blindly.
So basically you have the situation where people will take the new drug anyway and you have the choice whether you want to test its safeness before they do.
If you do the test and it turns out to be unsafe, at least you have good arguments when you need to make the decision.