I look at it this way .... the more people that get the virus, the closer we get to herd immunity. All the precautions taken from day one were only intended to slow the spread, not stop it. We have succeeded in slowing the spread to the point where health are facilities are not being overwhelmed. And that's all the masks, social distancing, etc. were intended to achieve.
Let's talk about herd immunity.
It is not a simple concept, it turns out.
Let me preface this post by acknowledging that I have agreed (in this very thread!) with the notion that all we were trying to do was "flatten the curve." To allow us to manage the disease without overwhelming our healthcare system, and to buy us time to develop better therapeutics, and possibly a vaccine. And those things are very important! But we must think a little more carefully about herd immunity, and what it means in the context of a novel disease.
The definition of herd immunity really boils down to having a R
0 (or some people write R
t) of less than one. That is, for every person that is infected, they go on to infect fewer than one more person on average. Under those conditions, the disease eventually dies out. If R
0 > 1, the disease spreads.
But our
behavior influences the value of R
0. I suspect that most of us have been thinking about "herd immunity" only under the conditions that we lived life, say, last year. Under those conditions, estimates are that something like 70% of people had to have
immunity to Covid to achieve R
0 < 1. (I should note that we don't even know yet if people who recover from the disease gain immunity, or how long it lasts if they do, let alone whether a vaccine will be developed.)
However, under a different set of behaviors, the transmission rate is different. So mask-wearing, hand-washing, etc., are not just buying us time, they are altering the dynamics of the spread of the disease, that is, they are altering the threshold when "herd immunity" is achieved. Of course, the "herd" is a different herd than we are used to; our behaviors would be different. But we as a society could
choose to be part of a herd where the disease doesn't spread as rapidly (at some social costs), and the herd immunity threshold is lower. Or we could choose to be part of a herd where the disease spreads rapidly, the threshold of herd immunity is much higher, and many more people are sickened or die.
Want to be convinced that the foregoing statements are true? With the framework discussed above in mind, compare these curves. I am not aware of any
intrinsic differences between the US and the EU that would explain these different outcomes.
