>>Now, consider what would happen if an extremely dangerous vaccine were introduced that resulted in 20 times as many AEs <i>of all types</i> as all the other vaccines to which it gets compared.<p>(emphasis added by me)<p>I am guessing here, but maybe the idea is that if there's an increase in AEs of all types, they're probably not caused by the vaccine.<p>I think the AEs are just bad things that happen after you get the vaccine, not necessarily bad things that happened because you got the vaccine.<p>Some places are prone to certain illnesses, and some drs/nurses are more inclined to report than others. So what they're looking for is a change in the proportion of AEs.<p>EDIT: I think the author might be making another mistake too:<p>>> Those unfamiliar with statistics will not recognize the problem, but when the different vaccines all result in similar problems (like myocarditis or blood clots, as has been noted), the chi-squared statistics will remain muted<p>The CDC document linked says:<p>>> PRRs compare the
proportion of a specific AE following a specific vaccine versus the proportion of the
same AE following receipt of <i>another vaccine</i> (see equation below Table 4)<p>The author seems to think this means "another Covid vaccine".<p>But just after that section, the CDC makes it clear that they really mean other vaccines in general, not other Covid vaccines:<p>>> CDC will apply appropriate comparator vaccines (e.g., adjuvanted vaccines like Shingrix
and/or Fluad for adjuvanted COVID-19 vaccines)