Why a SARS-CoV-2 variant that's 50% more transmissible would in general be a much bigger problem than a variant that's 50% more deadly. A short thread... 1/

2:40 PM · Dec 28, 2020

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As an example, suppose current R=1.1, infection fatality risk is 0.8%, generation time is 6 days, and 10k people infected (plausible for many European cities recently). So we'd expect 10000 x 1.1^5 x 0.8% = 129 eventual new fatalities after a month of spread... 2/
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What happens if fatality risk increases by 50%? By above, we'd expect 10000 x 1.1^5 x (0.8% x 1.5) = 193 new fatalities. 3/
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Now suppose transmissibility increases by 50%. By above, we'd expect 10000 x (1.1 x 1.5)^5 x 0.8% = 978 eventual new fatalities after a month of spread. 4/
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The above is just an illustrative example, but the key message: an increase in something that grows exponentially (i.e. transmission) can have far more effect than the same proportional increase in something that just scales an outcome (i.e. severity). 5/5
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Replying to @AdamJKucharski
So if my understanding is correct, Greater transmisibility is a far worse outcome than increased severity as the proportion of people effected is greater?
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The same proportion of people who are infected die, but far more people are infected in a given time/population.
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Replying to @AdamJKucharski
the unknown exponential is what will happen to quality of care, as transmission rates go up. We can’t staff the beds now as it is. In MS we are moving patients around the state to find critical care space in EDs FFS. Continuation of this five star flying monkey shit show...
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Thank you for your work. I can’t imagine what it’s like. As a therapist, I see the hidden costs to this pandemic and political incompetence. You’re facing life and death decisions every waking moment. Be well. ❤️
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Is, say, a 50% increase in transmissability consistent regardless of behavior? In other words, is it possible that non-mask wearers could see a 50% increase but mask wearers could see less of an increase?
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Masks don't offer much protection to the wearer. They mostly protect those around them.
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