Countries which abandoned BCG or never made it a part of universal vaccination programmes, are currently observed as heavily affected by the pandemic. However Eastern European blocks of former soviet influence like East German areas, are observed three times less affected than its western parts. Another example is Portugal which is finding itself much relieved. These are nations where BCG vaccination has been norm for over a century.
India, where BCG vaccination has been universally compulsory for almost 75 years, too can be positively observed as quite a good candidate to this case study, where Corona is so far unable creating havoc like we see elsewhere in many countries.
There is this interesting paper published much before term novel coronavirus was even heard, and it talks about BCG induced cross protection and trained immunity which goes beyond tuberculosis. BCG has been effectively found to reduce mortality among children and has been effective against risks of even respiratory tract infections and several other disease besides TB which it was primarily meant for.
Of course, the decisions to make it compulsory part of national vaccination programme was taken decades back and possibly could be one reason for it not getting serious social political attention for obvious reasons.
