4 Comments

Adam, this is an excellent reflection! Thank you for sharing.

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Very useful. Confident assertions from people unaware of these rules-of-thumb have been a big feature of the past few years.

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Great! thanks a lot. Intuition matters and good intuition comes from experience I suppose.

In Principle 2, wouldn´t the area under the curve be nevertheless the same? as we were saying in 2020 - let us lower transmission to flatten the curve and avoid peaks that flood health units, but in the long run the same number of people will get infected isn't it?

If I might add a Principle, it would stem from the serial interval (average time passed between symptom outset in an index case and symptom outset in secondary cases), assuming we manage to estimate it early, for example from household transmission. A short serial interval (being a proxy to a short generation time) would hint that, whatever the value of R for this infection, it comes about sooner than later, and thus the raise in the number of new infections should be expected steeper.

thanks again

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The area under the curve will be smaller if transmission is lower, because it reduces the final size of the epidemic, and the final size is larger than the herd immunity threshold – see figures 2-4 here: https://kucharski.substack.com/p/disrupted-dynamics

E.g. it's been estimated that reduction in social contacts during school holidays reduced the size of the 2009 influenza pandemic by around 20%: https://www.cambridge.org/core/journals/epidemiology-and-infection/article/influence-of-school-holiday-timing-on-epidemic-impact/5F0E4508895BB1A1B33DF9BA31FD7277

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