Thread by @oliverbeige

So this is my "invisible-vs-aggressive" evolutionary game theory working model: Aggressive "L" strain started earlier but was contained or invisible "S" strain moved faster. Countries differ in L vs S exposure by travel patterns, but most S spread undetected (asympto/mid sympto).

We mostly watch aggressive L expression (hospitalizations, deaths) with time lags. S is only caught in epidemiological (cluster panel) sampling. Also I don't think L is voluntarily killing off hosts (young people with severe responses) but intergenerational transmission does.

So I'm now trying to work thru three literatures with this, genetic mutation, geographic spread patterns, and disease expression, and haven't found a combined perspective yet. Hence still "working theory".

@threadreaderapp unroll

This is from memory bc I cannot locate the paper, respiratory diseases have "motivation" to keep their hosts alive longer than vector-borne diseases. Respiratories differ in whether the host shows symptoms (cough) or not. One produces more aerosols, the other remains undetected.

Now I am trying to work my way thru this. If it means what I think it means, it means...
Takahiko Koyama et al: Variant analysis of COVID-19 genomes (preprint)
researchgate.net/publication/33…

It means there are indeed two separate #COVID19 circuits: a slow-replicating strain that travels fast geographically with "travelers", and a fast-replicating strain that grows locally with "locals".

WOW. The visible and the invisible world.

L = "traveler" = aggressive, prevalent in 2019, replicates slowly = the visible world
S = "local" = benign, prevalent in 2020, replicates fast = the invisible world
#COVID19 academic.oup.com/nsr/advance-ar…