Thread by @federicolois

The arrival of a vaccine in the context of COVID can be modeled using game theory as a gamble over the expectation of the final death toll. Most countries will have negative payoff after August 2020. Change my mind. cc @LDjaparidze

Let's make it more interesting... Do you agree?

Context is king. For a gamble to exist we need to define clearly the parameters to observe the likely expected result. Let's start with vaccine efficacy (VE). What do you think is the range most manufacturers are looking for?

I am not an expert, but I happen to talk with people that are on the business. They tell me for a respiratory virus a 55% target is quite good. But, let's figure out if that is true. This is Moderna protocol: modernatx.com/sites/default/…

But you know why we would trust one manufacturer when we can get another one. This is Pfizer protocol: pfe-pfizercom-d8-prod.s3.amazonaws.com/2020-09/C45910…

If we modeled such a vaccine then, would be fair to use VE of 77% then?

Interesting. I was going to go god mode, but now I am interested. Do you believe the gamble should consider the vaccine VE should be:

Ok, so you choose to go lower than 77% will go 70%. To please the other side, I will make one more assumption to equalize. You can apply the vaccine to a 100% population overnight.

Let's say we have a time machine and we can come back to March when mitigations started to happen all over the world. How long would you be willing to mitigate before coming back to normal life in order to protect the vulnerable? Real Normal Life!!! January.

We are all burned out by mitigations. I get it, and yet we keep doing it for our vulnerable. So as context is king. This is what our most likely scenario is for Madrid with data until July looks observing continuous mitigations and the expected summer behavior observed at London.

The big question is how that scenario looks like in terms of what is really happening. Fitted from data up to July 9th, as you can see for September it predicts roughly 22 deaths per day. Currently is around 30 per day. comunidad.madrid/sites/default/…

If our 70% vaccine would be applied tonight to 100% of the population after 199 days after the initiation of lockdown. Do you think it would be able to beat 90 days of Sweden fitted trajectory?

OK, I have all people with yellow and blue shirts here it seems. Given the Stockholm trajectory was estimated to have the following isolation parameters:
- Vulnerable: 0.95
- Healthy: 0.2
Stockholm looks like this:

With under 1 deaths per day on average. Does that looks endemic to you?

Do you think the Sweden strategy is optimal?

What I can say is this: The optimal strategy for Stockholm no matter when the vaccine comes for our model does not exist. But, if the vaccine does not arrive before December there is a better strategy:
Vulnerable: 0.95
Healthy: 0.16

Does that looks like right there on the margin of error?

OK. For all uses and purposes, the Sweden strategy under our isolation model is optimal; unless of course you want to fix bad government policies. That's for another thread. Do you think the Madrid strategy would stand a chance against it?

The last graph of this series and the one that solves the gamble under our isolation model is quite complex. It is a level of abstraction on top of this linear thinking. We will respond to the following question:

If an oracle would tell me when the vaccine will be available. Is there an optimal strategy that would minimize the death toll given that date?

But, it doesn't end there. At the same time is good to know how other usual strategies found in the wild would fare under the model.

Isolations:
- Very strict: 0.9 (Sweden on vulnerable)
- Strict: 0.65 (Lockdown on average, Masks)
- Moderate: 0.4 (No Schools, Masks)
- Almost normal life: 0.13 (Schools, No Masks, No stadiums [???]).

QED. With very general assumptions (remember I wanted to go god-mode), after August on Madrid even if our magik vaccine comes; under our epidemic model from the point of view of game theory the expectation is that it will be a losing proposition.

Do you want to know if it is possible in 90 days to correct government policy mismanagement?