Different studies have different scopes, recent studies in G20 countries are essentially trials in largely vaccinated populations.

These are also trials in regions with relatively low rates of parasitic worm infection.

The early meta studies looked at trials in poorer regions of non G20 countries and showed the benefits of killing parasitic worms as increased resistance to flu, COVID, etc, etc across the board. Post worm dosing survival rates for most things increased compared to regions that didn't receive dosing.

These early studies are the main reason we see results such as the graph in a peer comment - killing worms improves COVID survival for those that had worm infestations to begin with.