Comment by tripletao

This isn't an RCT and COVID mortality is no longer high, so the effect on all-cause mortality is almost entirely confounders. So that result just means people 18-29 who chose to get the COVID vaccine have other characteristics that result in the much lower mortality from non-COVID causes.

I'm not sure why. The top causes for that age group are usually non-medical, accident, suicide, or homicide. We might speculate those would anticorrelate more strongly with the prudence that leads people to get the vaccine than unavoidable medical causes, but looking at the V, W, X, and Y causes from Table 2 that doesn't seem to be true. I guess it could be true but only for the 18-29 group (and if it's not then what causes are responsible?), since they don't break that down by age.

The "problem" is that vaccine recipients are so much healthier overall than non-recipients that the vaccine would have to be spectacularly unsafe to offset that. So this analysis doesn't actually tell us much, but it's consistent with all other evidence that the vaccine is safe.