Pattern-chaser wrote:It is about people mixing with other members of their community, not mixing with rocks and statues.
Correct! It is about immune people mixing in with vulnerable people to give a protective effect to the vulnerable people. And if we un-mix (remove) immune people from a group of vulnerable people, then there will be less (or no) protective effect to these vulnerable.
So now the million dollar question is - WHAT specifically causes this "protective effect"?
Pattern-chaser wrote:If 60% of the people I mix with are infected, that results in a certain risk of my being infected. If only 40% are infected, and I mix with them, as before, my chance of becoming infected is lower. If 90% of them are immune, and non-infectious, then my chances of infection are reduced even more.
Not quite. According to science, once the herd immunity threshold value is reached within a given population, then this theoretically provides protection to everyone (including all the vulnerable).
It has more to do with the Rt value (rate of transmission). Once the net average Rt value within a given environment drops below 1 (i.e. <1) then more of the virus is being removed (or dying) than created (or shed) within that environment, effectively stopping the transmission of the virus.
Pattern-chaser wrote:At some percentage value of infection/immunity, the rate of infection (and therefore transmission) falls to the point where the virus outbreak starts to collapse, because the viruses I breathe out (if I am infected) can't 'find' a new and vulnerable host to infect before they die. This is herd immunity, I think.
I am not sure I follow exactly.
1. If we REMOVE immune people (whose Rt value is <1) from a viral contaminated room leaving only vulnerable people (whose Rt value is >1), then we will increase the density of the virus per person in the room, and increase the overall room Rt value (the average transmission rate in the room), and thereby DECREASE the "protective effect" to the vulnerable, (...meaning MORE DEATHS).
2. If we ADD immune people (Rt <1) into a viral contaminated room of vulnerable people (Rt >1), then we will decrease the density of the virus per person in the room, and decrease the overall room Rt value, and thereby INCREASE the "protective effect" to the vulnerable, (...meaning LESS DEATHS).
3. Once the room's net Rt value is 1 (or less than 1), then this effectively stops the virus transmission, effectively making it safe for everyone.
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AND, so this is why it is SO IMPORTANT to un-mask (and not-socially distance) our healthy immune population. Keeping our healthy population (including those recently vaccinated, and those previously infected) masked and socially distanced only creates MORE DEATHS of our vulnerable people.