If we return to the subject of the thread, I suggest it would be irresponsible to hold the Olympics this year. Going to the example of the so-called "Spanish Flu" of 1918 (and yes, it was quite different, different times, it affected 20-35-year-olds disproportionately etc.), we can expect waves of the infection.
The first wave of the 1918 flu came (probably via wildfowl to farm animals to a farm worker who became a cook in the army) from an army camp in Kansas, spread through more military bases, and went on-board troop ships to the European battle front. This was in March 1918. From there it spread, via repatriated victims to other countries in Europe, and the world.
It seemed to have passed by early August, but then came back in mutated and highly dangerous form, from another US military base near Boston, and was transmitted through Europe in exactly the same way as the earlier version. This was now the very vicious form, that killed more people than both World Wars.
The third wave came at the end of the war. Tragically, because everyone was so happy, not just about the war but the expectation that the flu was dying down as well, they all went out into the streets in one of those spontaneous expressions of happiness, hugging and kissing strangers. This kick-started the virus again in November, and it carried on at least until the middle of 1919, possibly longer.
It is very easy to draw comparisons with the victory celebrations and the Olympics due later this year. There is a well-known sports commentator's quote here about the 1966 World Cup; "They think it's all over...*", referring to crowds rushing onto the Wembley pitch before the final was actually over.
(The other very real comparison is with governments, who tried to downplay the seriousness of the outbreaks, due to "wartime morale" at that time, and sheer cussedness now. The reason it was called Spanish Flu was because Spain was a neutral country, and thus the disease was reported in Spanish papers without government intervention. Foreign journalists in Spain started calling it the "Spanish" flu, and the name stuck.)
I am classified as having serious under-lying issues (diabetes, asthma and heart) as well as being nearly 70. I do not look forward to spending any more time than necessary isolated in my home. But I really don't want to rush back onto the pitch before "...*it is now".
Information from BBC 2018 documentary
"The Flu That Killed 50M"
https://www.bbc.co.uk/programmes/p06l5h0x and
https://www.thoughtco.com/1918-spanish-flu-pandemic-1779224 (accessed 17 March 2020)