Early Immune Warning System: A Bit of Evidence

I have proposed that three things — a tendency to touch each other (e.g., shake hands), a tendency to touch near our mouths, and our tonsils — together form an early warning system for our immune system. The early warning system helps the immune system get tiny exposure to microbes circulating in the community. It performs self-vaccination. Like ordinary vaccination, exposure to tiny amounts of Microbe X protects against exposure to a large amount of Microbe X.

In Daniel Everett’s anthropological study of the Pirahã people (Don’t Sleep, There are Snakes: Life and Language in the Amazonian Jungle, 2009) he says the Pirahã “all touch one another frequently” (p. 85). “They loved to touch me too.” He has never seen kissing but “there is a word for it, so they must do it.” This supports the idea that a tendency to touch others is widespread.

If this theory is true, reducing microbe exposure to zero (e.g., sterile food) is a seriously bad thing. It’s been proposed that the polio epidemics of the first half of the 1900s were caused by cities becoming too clean.

Evidence from ants.


6 Replies to “Early Immune Warning System: A Bit of Evidence”

  1. in a previous post (what to do about antibiotic resistance?improve immune function) you mentioned this idea( listed as 3 there). You said there “So it’s not obvious that outside of hospitals more hand washing is a good thing”. I find it interesting because frequently I see that even people who criticize some aspects of cleanliness when it comes to washing hands they are mainstream.If you can make it more precise I think it will be even more interesting.for example what do you mean by more, 1)more than conventional guidelines suggest, 2)more than someone who doesn’t wash them even after using a public toilet,your meaning of more, is closer to 1 or closer to 2?

    Seth: Closer to 1. But, actually, it isn’t clear at all to me what level of hand-washing is best.

  2. Perhaps sneezing is also a sharing mechanism, not because of vaccination effect, because of the cappacity to spread the disease in a not so virulent form. If the microorganism can infect the most quantity of hosts without a very agressive strategy it will be stable and not evolve to increase virulence. If killing hosts is what infects the most hosts it will be selected to do so. Maybe the body developed this sneeze reflex as a prophylactic measure. Facilitating the spread of non-lethal diseases and in doing so preventing them from being seduced by the lethal option which is a very juicy alternative.

    I once saw a talk which described how when a country with cholera controlled the sewage in a way that corpse & dying patient contaminated water was prevented from reaching the public supply, forced the bacterium to be less virulent, keeping people alive more as the fittest way to survive. The strategy didn’t eradicate, but attenuated the disease. Better to have seasonal flu than SARS.

    Seth: Good points.

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