> if that's not direct proof of a systematic effect and success then I don't know what is

Two graphs. One for a country with a box, and one for one without.

Interestingly people have made such graphs, and there is no difference.

How about something that accounts for all the other medical advances over the past century or so? I'd say they likely had some input on that graph.

I'm pretty sure the discovery of penicillin had something to do with the drop in infant mortality as well.