COVID-19 and the great Chinese puzzle, by Jacob John.
Virus spread in China reportedly stopped by the end of the third week of March, with no new SARS-CoV-2 infections arising locally since then. China is now gearing up to prevent virus transmission from citizens returning from other countries. If only 90,000 were infected among a 1.4 billion population, the proportion was only 0.0065%.
Here is the puzzle: for any epidemic, its downturn consequent to high herd immunity requires about 70% infected and immune. Every second person in the community will then be a dead-end for virus spread.
What proportion of the Chinese was actually infected? The proportion of 0.0065% is unrealistically low for the visible shift in epidemiology. If 70% were infected, there were 980 million infections. This extraordinary range is the puzzle.
Perhaps they crushed the curve, rather than built up herd immunity? Radical thought, I know…
Or perhaps something more devious went on, and the West got fooled into thinking the virus was much worse than it is. Or perhaps something even more devious. Conspiracy theories abound, but IMHO none are yet rising to the level of reasonably likely.