I urge readers to look closely at COVID new cases before and after March 1 - note different scales of panels below. As of Mar 1, more cases and more new cases in both China and Korea than Italy and US. Since then, US/Italy levels exploded to levels much higher than China ever had 
2/ many readers and commenters assert that you can't trust the Chinese data because of the wickedness of CCP. IMO wickedness of CCP and also China-Taiwan politics are topics for another day. For now, I don't have the faintest interest in any comment which grinds a political axe.
3/ even if Chinese cases were under-estimated, I don't think that there is any reasonable doubt that they've managed to reduce new cases on the scale indicated by statistics. IMO Korea's relative success adds to credibility of reported dramatic reduction of new cases in China.
4/ the only really important question of public policy right now ought to be: what did China and South Korea do differently than US and Italy in order to stop the virus? Whatever it is, we need to do it.
5/ Masks are commonplace/required in China and South Korea. There's plausible reasoning that they prevent exhalation of virus by asymptomatic carriers and thus limit spread, even if they don't provide magic protection for wearer. I don't understand health authority reluctance
6/ according to reputable reports, hydroxychloroquine was part of Korean treatment protocols. The virus exploded from 450 cases to 35000 cases in New York City in only two weeks. There are a lot of places (including Toronto) at around 450-500 cases. If something was used in Korea
7/ that's good enough for me. I don't want any more dithering from public health authorities. I say that they've got enough to go on to mandate hydroxychloroquine (plus zinc or Z-pac) right now and, if the clinical trials bust, then they can cancel it.
8/ given the low cost and low risk of hydroxychloroquine and the insane explosion of caseload, the onus on health authorities is reversed. Unless they can show that hydroxychloroquine has negative consequences, it should be used.
9/ here's the same comparison for new deaths. Again, scale in right panel is SEVEN times left panel. New deaths in both Italy and US both MUCH higher than China, Korea ever were. Also still no sign of new deaths leveling off in either US or Italy. Very worrying.
