Herd Immunity

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Herd immunity means that enough people have had a disease, that the contagion can't spread and dies out. (Basically the effective R0, or how many people each person with the disease passes it on to, is less than 1 other person). This belief leads to misconceptions.

  • Some people think that needs to be 60 or 80% of the population. Oversimplified: a disease with an R0 of 3 would require >66% of the population to have immunity so that more than 2 out of 3 people it tried to pass it to, would already have immunity -- dropping the transfer rate below 1.0 and the disease would die out. Basically, true, but there's more to it.
  • Herd immunity stacks on other measures: so if you can reduce a contagion to spreading 1/2 as fast by social distancing, hand sanitization, masks, etc., then the R0 of 3.0 is now effectively a 1.5. Which loosely means that if >33% (1 in 3) people already has it, that slows it by an additional 33%, and you're below 1.0, and it would die out. Behavior/culture modifies transfer speed (R0).
  • Distribution vectors also matter. Not everyone is equally at risk from everyone else. We have cliques and social circles (clusters/tribes). Someone in BF Idaho doesn't have an equal threat from someone in NYC or Wuhan as from their neighbor or family, because they interact with them slower and less often. If the people immunized are all the people that travel from NYC to BF Idaho, then it doesn't matter if anyone in Idaho has herd immunity, because you cut off the threads of transfer. So inoculating the 5% that travel, could offer significant protections for the other 95% of the sub-population.

This is why the 1918 Spanish Flu Pandemic only infected only 30% of the population -- and NOT 80% required to get theoretical herd immunity.


There was a common sense post that some claimed was "controversial" that basically explained that since 1/3rd of people are responsible for over 2/3rd of interactions, her immunity happens faster than requiring everyone to be equally immunized. The idea is simple and obvious, even if the numbers can be disputed -- but since some people either don't understand common sense, or want the problem to be bigger than it is, they attack sources that point out obvious things like this. [1]

❝ One thing both economists and epidemiologists seem to be lacking is an awareness of the problems of aggregation. Most models in both fields see the population as one homogenous mass of individuals. But sometimes, individual variation makes a difference in the aggregate, even if the average is the same.

In the case of pandemics it makes a big difference how the infection rate varies in the population. Most models assume that it is the same for everyone. But in reality, human interactions are not evenly distributed. Some people shake hands all day, while others spend their day in front of a screen. This uneven distribution has an interesting effect: those who spread the virus are the most likely to get it. This means that the infection rate looks very high in the beginning of a pandemic, but sinks once the super-spreaders have had the disease and got immunity. Also, it means herd immunity is reached much earlier : not after 70% of the population is immune, but after who are involved in 70% of the interactions are immune. At average, this is the same, but in practice, it can make a bit difference... ❞
🗒️ NOTE:
Simulations that don't show this clustering, or high transmission versus low transmission vectors, are fundamentally dishonest/misleading.


📚 References

The Coronavirus is named after the fact that under a microscope it looks like the surface of the sun, with lots of little protrusions and bumps. These are series of diseases, but the one everyone is talking about for now, is the Chinese (Wuhan COVID-19 for COrona VIrus Disease circa 2019, or SARS-CoV-2) that's going pandemic. While the CDC, WHO and FDA all blew their response, we've never seen a more effective response to a pandemic, and the U.S. outperformed most of the world in objective metrics. But as to be expected, partisan Democrats and their media never let an opportunity go to waste: to politicize, polarize, divide and undermine the American economy and people.
We can't communicate effectively if we don't agree on what words or terms mean. Cultural Marxists decided that since they uusally can't win through honesty, logic, history and facts, they could win by twisting/perverting meanings (especially in popular culture and colleges), to distort every discussion into a debate on pedantics, or use truthspeak as a litmus test for who is properly indoctrinated/compliant. This section isn't intended as a comprehensive dictionary, but just to stop that gaslighting, by defining what I (and often history/society means or should mean) when using a term. Not what the far left is trying to re-invent terms into.