Clinical research selects the number of subjects under treatment based on desired statistical power (i.e. the probability of rejecting the null hypothesis when the null is in effect false, given a certain confidence level). Usual guidelines are for power to be no less than 80% (e.g. here). I wonder whether the Covid vaccines under study have a higher or lower required power than usual. I have found, unsurprisingly, no information available on the actual number of subjects, let alone the power assumed, by Covid trials currently undertaken.
Is anyone aware of the assumptions in terms of power used for some Covid vaccine trials?