NorthWest Biotherapeutics Inc (NWBO)

[exwannabe]

But it's in use in most of the world, with a few countries being notable exceptions. Curiously enough, those few are the ones with highest deaths to cases...

Source for that assertions? Here are the numbers I can find:

From this survey by a health care data company that does not look to have a horse in the race:

Hydroxychloroquine usage amongst COVID-19 treaters is 72% in Spain, 49% in Italy, 41% in Brazil, 39% in Mexico, 28% in France, 23% in the U.S., 17% in Germany, 16% in Canada, 13% in the UK and 7% in Japan

Combined with numbers from worldometer we have:

 
 Country   HC%    Cases(x1000)  Deaths    D/C % 
 -------   -----  --------      --------  ----- 
 Spain     72%    278           27,709    10.0% 
 Italy     49%    226           32,007    14.1% 
 Brazil    41%    225           16,853     7.4% 
 Mexico    39%    52            5,332     10.3%  
 France    28%    180           28,328    15.7% 
 US        17%    1,550         91,981     5.9% 
 Germany   16%    177           8,123      4.6% 
 Canada    13%    78            5,842      7.5%     
 UK        7%     246           34,796    14.2% 
 

I see no pattern here. You can point to the UK, but I can also point to US and Germany which have low HC use and low case mortality ratios. And the highest user, Spain, sits in the middle.