Asked my virologist friend.
‘Again, as with chloroquine, mostly anecdotal evidence to suggest it does anything‘
Me: could you venture a biological reason why it may work?
‘ It’s most likely low level cross reactivity or an immune boosting response to an adjuvant in the vaccine. My bet would be the latter’
Edit: Oxford microbio mate (you all wish you could be on this politics WhatsApp) said this in addition:
‘BCG is a miracle vaccine, has all kinds of beneficial effects outside of it’s main use, which ironically it isn’t particularly effective at.
So I don’t have too much trouble believing it‘