I was thinking about this since I read the article. The number you state seems to be 0.5% of total subjects. To my understanding, this is not how "p < 0.005" is employed.

If we take the control group, we have P(Corona)=90/15000. The likelyhood of getting as an extreme result in the vaccine group is then P(0 cases) + ... + P(5 cases) = [math and statistics] = the actual p-value.

How did you determine the statistical significance in your post?

The caveat is that “dczot” doesn’t know what a caveat is.