Out of 45,000 people, only 86ish people got infected in the trial arm? Isn't that too few? Even for the control arm, that's still only 774 people infected.
That's not true, population size absolutely 'enters into the math'. 9 vs. 85 does not give the same result independently of whether N=94, 200, 2k, or 2B.
It affects confidence, and potentially the result of the test entirely. I won't be more specific because stats was never a strong suit and my memory's hazy, but I remember enough to know it matters!
I'm thinking that 85/21,750 or 0.4% of the controls developed the disease (vs 0.04% of those who received vaccine).
It does seem low for the US where you have 3% of the population had disease already in 2020. Perhaps more data came from Germany? Or it could be they measure not just PCR +ve results, but antibody levels and/or severe symptoms?
Those are the numbers that matter, statistically. If the total number of people in the study were 2 thousand or 2 billion doesn't enter into the math.