This is very interesting indeed. From a purely statistical perspective, this is as close as we can get to a "natural experiment" ..... https://twitter.com/dasgobardhan/status/1248903842516754432

Continuing on my twitter pontificating (warning: it is no more than that), however, the map of BCG countries is interesting. Italy never had BCG but other Europeans discontinued it. So, there should be a correlation between impact and age. And China??? https://www.researchgate.net/figure/Map-displaying-BCG-vaccination-policy-by-country-A-The-country-currently-has-universal_fig2_50892386

Iran is a BCG country as well, but Australia is not. But latter fared better despite being full of Chinese tourists in Jan. Even Chinese data could be gleaned for impact of disruptions in vaccination due to Cultural Rev etc. So, the Spain/Portugal comparison is not full story.

So, on second thoughts, the Spain/Portugal comparison is not good enough. Reminds me of why I am suspicious of grand conclusions based of single point RCT studies.

So, one other natural experiment can be done in Europe (ex-Italy). Look at when BCG stopped being mandatory - and look at the age profile of victims. Unlike Italy, the correlation with age would be inverse. @ShamikaRavi - your thoughts?