>The MMR-version of the same "this is the magic key" story seemed much more promising (except for Iran) ...
Iran only administered a single MMR shot and consequently had lower levels of protection.
https://www.sciencedirect.com/science/article/pii/S120197120...
Italy had a inadequate MMR vaccination, too:
https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5243a4.htm
See this report on a multi-country analysis from last week:
https://www.contractpharma.com/content-microsite/covid-19/20...