Operation Warpspeed addressed that by running a very large stage 3 trial. One reason that isn't normally done is the high cost of such a large trial.

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lixtra 2 hours ago | parent [-]

Would that large trial have shown the cancerous effect of smoking? If not, do you then agree that some possible adverse effects were not checked for and could have slipped through?

	▲	RandomLensman 2 hours ago \| parent [-]
		Don't know. But would standard smaller trials have captured it? We are kind of back to my initial question that is conceptually unrelated to the vaccine trial: do you need trials to run into millions or billions of participants or into decades if you want to capture certain (rare) things?.