“Precautionary principle” via Wikipedia: The precautionary principle (or precautionary approach) is a broad epistemological, philosophical and legal approach to innovations with potential for causing harm when extensive scientific knowledge on the matter is lacking. It emphasizes caution, pausing and review before leaping into new innovations that may prove disastrous. Critics argue that it is vague, self-cancelling, unscientific and an obstacle to progress.
I am sympathetic to this analysis but am also wary. Like in the old joke about an engineer's child asking him why the sun rises from the East and the engineer replying "It works, don't touch!", so have I at this stage in my life, have become very wary of sudden changes and disposing of systems that may seem antiquated and unnecessary but turn out to be Chesterton's fences. Plus the fact that system design to be successful has always and everywhere to be an iterative process. I know you're prompted to write this in particular in the light of the 11 months it took for the vaccines to be almost approved , but I can easily see a huge downside risk of rushing one bad candidate that would set us back way more than the damage done while waiting for the trials to be conclusive.
I love this post. I keep coming back to it and I've been coopting this metaphor for a while. If you want to see your conception carried to extremes, take a look at the DoD.