A thread on the folly of "herd immunity" which I need to get off my chest:

To begin, herd immunity by natural exposure to a pathogen is not a strategy to end a pandemic; it is in fact a logic fallacy in regards to COVID-19

To occur it requires some assumptions.

/1

The first assumption is that exposure creates some form of effective immunity. We do not know to what extent and what duration any immunity is created after infection to COVID-19. There have already been documented re-infection of previously infected people.

/2

The next assumption is that population exposure occurs broadly and quickly enough to provide the heretofore unknown immunity to enough of the population to breach the "herd immunity" threshold for the virus (currently believed to be 60-70%). /3

A third assumption is that exposure to the virus is evenly spread throughout the population, crosscutting demographics and geographics. Without this, there will always be population enclaves with greater or lesser exposure/immunity rates. /4

Finally, the population would have to remain stable in number, in other words, not grow at a rate which exceeds the spread of the virus.

Births, immigration, cross-border travel would have to be brought to a minimum for an undetermined period of time. /5

Let's assume the US was to promote herd-immunity alone. That would require no immigration or expatriation, no entry visas (of course who would want to visit us?) and of course other countries would likely turn us away or require quarantine prior to entry (already happening) /6

It is important to look at the history of viruses for guidance. Think about varicella (chicken pox): until there was a vaccine, it was just considered inevitable that people will get it at sometime in their lives. There was no "herd immunity" until a vaccine was developed. /7

In fact it is hard to find any example of any pandemic which was resolved by "herd immunity" alone. Theoretically, if you had a stable, cloistered, isolated population, on a remote island for example, then herd immunity could occur,if the conditions were right. /8

This just glances the surface of the flaws in logic regarding herd immunity, there are other considerations as well such as non-human vectors, for example.

A more likely scenario instead of herd immunity, is that the virus would simply become endemic /9

And endemic virus would never go away, it would simply rotate through the population, stochastically mutating with varied degrees of pathogenicity and virulence. /10

So anyone promoting herd immunity is taking much for granted, assuming facts not in evidence and is basically willing to gamble with the lives of millions of people.

To what end is the question...

Thanks for reading

/fin