Our immune system has been quite a central topic the last couple of years. When Philippp Dittmer wrote his take on the subject, I was interested, as Kurzgesagt is one of the best science Youtube channel there is!

Discussion

The book is split on four main parts, two presentation and two analysis. They will all build on top of the previous one, which makes sense as the immune system is a set of interrelated systems.

The first part is simply the presentation of what the immune system is and what the human body is. The book is mainly explaining the immune system through metaphors, and they are simple enough to allow anyone to understand the basic mechanisms that are at play. It’s a simplification, of course, a comparison, to allow a better understanding.

The second part handles the first few layers of defense in the human body and explains this through the invasion of a bacteria. It explains really well how the innate immune system works and what it can do. I appreciated the presentation of the systems that are also responsible for some of our adverse reactions with the neutrophils and we can already understand from the explanation how the first COVID waves were so destructive. The later chapters with the adaptive immune system are just as interesting although they don’t explain yet how we loose immunity in some cases.

The third part describes a virus infection. On top of the other systems, this is when I started understanding what a friend described when they were talking about the COVID vaccine, and the fact that cells present bits of what they are doing at their surface, which can be used by the immune system to kill these cells. I liked the interferons explanations, and when read through the prism of the pandemic, it helps understanding why some treatments helped and other didn’t!

The last part is more general, talking about the balance to achieve in the immune system, from too weak to too strong and why trying to tweak it ourselves is not a good idea. We should  not boost it, just help it in keeping a good balance. The COVID chapter is probably too short and too old already, although we knew from the start that immunity in coronaviruses doesn’t last as long as for other diseases.

Conclusion

Yes, the book is not perfect, yes, the COVID section is missing a section on immunity waning, but all things considered, with no controversy in the book and stays at the current state of the art, it’s a great introduction to the field, light, cautious, but fascinating.