2 scents > NZ: As synthesized in the Cochrane systematic review
as I suggested, just go to Cochrane reviews site – that has many years of expertise in doing meta-studies – and read those meta-reviews yourself.
Someone counted that a 1 mln of professionals of different disciplines published or commented on COVID, all in good faith, but often outside of what they really know (that includes me). So, many people are trying obvious – aggregating someone else’s studies. Cochrane knows how to do it, they test for potential pitfalls and biases, others might not.
To quote common seychel, you don’t do your own dentistry, don’t rely on amateur meta-studies.