Is It Possible That the New Vaccines Will Work?

i asked this pole on twitter, obviously very unscientific. I'm then i asked this question to see if i could get a percentage. There will be some squirming. All right. Let's go extreme opposite. Suppose you knew that a hundred % of every kind of pharmacutical drug that had ever been created and approved by the fta was later found to be ineffective. What would be your natural guess as to whether it's likely that they worked? Pretty high right? If everything had worked before, even if they had a compressed schedule for testing, which they did with the vaccines, you think, well, yes, this is more risky because they don't have the long term