Thread by @evokerr

I’m growing increasingly concerned that some advice to socially distance is being targeted only at the most vulnerable within our community (w/ high #COVID19 complications risk). Low-risk individuals also have a big role to play here & we really need to be emphasizing this. [1/8]

To illustrate the point, @ocornejoPopGen and I built a model (SEIR w/ high- & low-risk groups). Because low-risk people are more common, their behavioral change can have *greater* impact on lowering peak number of infections. Ideally, everyone limits interactions, but... [2/8]

...we shouldn't ignore effects of low-risk individuals changing behavior. Let’s focus on high-risk infected cases (y-axis scaled as before). If only low-risk individuals limit interaction, this has greater impact on *high-risk cases* than if only high-risk individuals do so [3/8]

Why such a counter-intuitive result? A nice metaphor for social distancing (HT: @gregggonsalves) involves breaking the propagation of fire in a set of clustered matches through separation. Let's expand this metaphor to understand the findings from our simple model... [4/8]

Consider this set of matches near a flame. To avoid an all-out blaze, would you focus on moving back green or red matches? Whether any given match ignites depends not only on its position, but also on how many other matches are lit, a factor altered more by majority retreat [5/8]

Similarly, social distancing practiced by a majority fraction of a population can be a powerful way to mitigate the spread of disease. Of course, it would be best for all of us to embrace sensible measures to limit transmission (social distancing, hygienic practices, etc.). [6/8]

However, to expect the most vulnerable people (those most in need of support) to be the only ones to alter behavior is not only unfair, it is a severely suboptimal approach from a public health standpoint. Low-risk individuals also need to be part of these efforts. [7/8]

Social behavior w/ low *personal* health risks can have a high impact on *public* health. Proactive measures by low-risk individuals can carry profound & positive consequences. It is up to all of us, together, to #FlattenTheCurve & protect the most vulnerable among us. [8/8]

[Addendum] For anyone who would like access to the R code for the SEIR model @ocornejoPopGen and I developed, it can be found here:
github.com/evokerr/SEIR_R…
Explanations of the parameter values used and core model structure can be found here:
github.com/oeco28/SEIR-MO…