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By now you have surely heard about “flattening the curve” and seen the pretty picture that typically comes with it. A variation even made it into the New York Times last week.


The original argument/idea behind this picture crudely goes as follows. The COVID-19 pandemic will be over once a critical fraction (“the point of herd-immunity”, estimations vary but converge typically around two thirds) of the population develops immunity against the virus. Comparing death rates from regions that were surprised and thus overwhelmed by the virus (e.g. the Wuhan region in China or Lombardy in Italy) with those who were well prepared and hence faced a smaller amount of cases per capita (e.g. South Korea or the remainder of China) teaches us that pushing the number of serious cases below the capacity of the local healthcare system saves a ton of lives.

In order to achieve herd-immunity, however, the fraction of the overall population that gets infected with the virus does not change. This is depicted by the fact that the areas below the curves above are approximately equal. While this sounds like an intriguing argument, it is not realistic. Crude calculations show that it could take years to decades until we reach that point.

What we are (or should be) after, is, in fact, a reduction of the area under the curve itself, not stretching the curve over years. Instead of achieving herd-immunity, our goal should be to eradicate the virus as quickly as possible. While we may hope that summer, a vaccination or medications will put an abrupt end to the pandemic, these are hypotheticals that are far from certain to manifest. China with its rigorous policy of social distancing is the prime example after which other countries should model their response to the virus. The Washington Post published a neat little simulation, misleadingly also referring to flattening of the curve , that exemplifies the argument and generates these neat gifs:

covid_sim Not only does the curve get stretched by means of social distancing but the area under the curve, i.e. the number of overall infected people, diminishes. Since I trust that you neither want to see exorbitant numbers of older people and the odd younger ones die, nor that you want to sit at home for the next fifteen years, let’s give it some effort for a change and stop spreading dubious conspiracy theories.

Waiting for a vaccination or effective medications is a dangerous game.  Social distancing does not only save lives, it also allows to get back to our lives significantly faster. If we want to eradicate the curve, however, governments need to take more decisive (and also painful) action than if we wanted to stretch the curve. In particular, it is insufficient to just provide recommendations and it is certainly counter-productive to propagate herd-immunity. No country should witness world-war like scenes in its hospitals due to the indecisiveness of world leaders.