I'm reading a few threads showing that in most cities where 20%+ of the population got antibodies, COVID cases drops.
That's great.
However, it might not be as simple.
Some considerations in this thread (1/N).
- They reached herd immunity in a few cities only, and new cases came from other cities.
- They are far from herd immunity, and the good results were obtained by a change of behaviors (lockdowns, masks, distancing, etc)
Is this compatible with herd immunity? Is it due to herd immunity being reached in some social pockets but not in others? Or…
- antibodies % in a population
- behavior (social contact, masks wearing, etc)
- quantity of virus in the population
Could it be for example that Sweden got it better than Italy because there was less virus in Sweden than in 🇮🇹 (so viral loads were lower)?
For example, cases might decrease when 20% antibodies is reached OR when behaviors reduce the amount of virus in a town below a given density.
Or, the % of a population with antibodies to reach herd immunity can depend on viral load.
Either way, I believe that not all lockdowns are equal, not all distancing is equal, not all immunities are equal, not all viral load is equal, and those nuances are very, very important.
Most questions raised by the thread still apply though.
Given a case, how much virus is he spreading?
It depends on how fast he is identified, on whether he wears face masks, on whether his town implemented social distancing, on the viral load that infected him, etc.
Many stats miss this.
Only knowing how many salespeople they have is not enough to predict how many apples they will sell. What do these salespeople do? Where do they sell? How much stock they have?
Same with COVID cases & spreading