For those like me who didn’t already know, a Doula is someone supports a woman and her family during pregnancy, childbirth and beyond. It is not medical role but rather provides emotional and practical support. Now someone called the Holistic Doula has developed her own model to show how natural exposure to an infection leads to immunity in the community – herd immunity. Apparently the image is doing the rounds. Unfortunately it is not really a very good reflection of reality. Let me count the ways:
- As per holistic doulas model, if this were measles and no one was immune and everyone was 5-9 years old and these 5-9 year olds all lived together without any adults, and none of them moved in or out of the bubble, for the rest of their lives, then hula the doulas model sort of works. The proportion with sequelae needs adjustment but all in all not too bad. Of course around 15 percent or so of infected kids would need to be hospitalised. Not sure if there are any hospitals in this bubble and because our population are 5-9 years old I suspect there are no doctors and nurses to look after them. No mummies and daddies either for that matter. Hmmm.
- Holistic doula has 52 little people and points out that nobody died or ended up with long term sequalae – awesome!! Except for the fact that in NZ (for example) there is a population of 4.3 million not 52. In the real world that is 4200 dead, 4200 brain damaged, 630,000 hospitalised, 42 additional dead later on with subacute sclerosing panencephalitis (brain turns to mush and death always ensues) and a myriad of other miseries. The excellent news is that most people survive and remain immune!! Sadly, most of the seriously immune compromised people have died.
- Communities do not live in a closed bubble. People come and go so firstly you need to show people moving in and out of the picture.
- You can’t have a population of just one cohort of 5-9 year olds in the real world.
- Some of the people coming into the picture are new births therefore the non-immune are continually increasing.
Here is said model from Holistic Doula
In the absence of an immunisation programme epidemics occur once sufficient non-immune people have accumulated. These epidemics are small or large depending on the proportion of people immune. How many people are seriously adversely affected is purely a numbers game but the risks are always the same. Measles is an easy disease to model and it has been done many times. The morbidity and mortality during epidemics continues to support the models.
I do heartily recommend “Herd Immunity”: A Rough Guide by some seriously good experts for those interested or even contemplating drawing their own pictures. And if you really want to simulate measles virus or any other infectious disease there are a range of cool simulators available on line. Personally I have found Plague inc by NDEMIC creations is about the right level for me! and have it on all my devices for those times when destroying the earth is required.