As with every good journey, arriving somewhere is as important as leaving in the first place. We saw a great many things and many complex and intertwined systems. We got to know all your surfaces, inside and outside, and their intricate defense networks. We met your soldiers, from black rhinos that are calm most of the time to crazy monkeys with machine guns.
We observed how your immune system jumps into gear when your body is breached and wounded, how multiple layers of complexity work together to organize exactly the correct type of defense over distances that are enormously large for your tiny cells. We visited the largest library in the universe and the deadliest university that you carry with you without even thinking about it.
We witnessed a sneaky attack on your most inner self by an army of viruses that was as effective as it was cruel and uncaring. We explored how your immune system remembers its battles and how we as humans can assist it with that. We took a look at what happens when your immune system fails or when it overcommits and becomes the source of disease and damage. And while we did dive pretty deep at times, there are so many more amazing places and systems we did not have time to visit. But if you made it to this page, you have gotten a real roundtrip through your own body and some of the most important things you probably never thought about.
An annoying thing about the immune system is that you need to understand multiple things at the same time before the whole system begins to make sense, and before its true beauty reveals itself. If you understand Macrophages and MHC molecules and cytokines and T Cell receptors and the lymphatic system and antibodies, then they all combine into an amazingly elegant system that makes so much sense and is pretty stunning.
But getting started is extremely hard because the immune system seems to be designed to be opaque and hard to grasp. I complained a bunch about the language of immunology and while that was hopefully mildly amusing to you, in reality, it was not so much for me. To research this book I had to read textbooks and academic papers with the speed of a first grader, just so I could keep up with what they tried to say. I can’t imagine a field that would profit more from cleaning up its language and making an effort to become more palatable to the general public. Because in the end, immunology is truly one of the coolest topics ever.
Science offers such a diverse array of topics that you can immerse yourself in. And in popular culture it is often the seemingly large topics and fields that are the most beloved. Space, for example, with its huge distances and black holes and gigantic stars, is an easy sell for documentaries and popular science books. But while space is nice and all, it has nothing over biology. Stars are dead clumps of burning plasma, and even the most complex and interesting one can’t compete with the wonder and complexity of the simplest bacteria trying to escape a Macrophage.
The immune system is not as pleasing, not as accommodating as other fields of popular science. It asks a lot of you up front. A certain investment of time and pain is necessary to get to the point where you can really appreciate it. And in a time where the expectation is that information has to be pleasing and easy to digest this feels like a lot to ask. Despite these challenges, the immune system is one of the best topics to learn about because of the fact that it is so complex and made up of so many layers that all interact in such ingenious ways—it is like a window into the universe itself. A window into the complexity that surrounds you and that you are a part of. You are incredibly lucky to be alive and to have a body that you can call your own. Or at least I feel that way.
So I would argue that it is worth the investment because the payoff is so amazing and I hope if you read this far, you feel the same. Once you reach the mountaintop and get a sort of clear picture of the immune system, the view is like no other. You get a taste of what it means to stay alive in a world that is a struggle between different forces that do not care about how you feel about them.
All of this beautiful complexity carries a hint of sadness. It stings a bit to know that life is too short and too busy to truly learn about all the layers that make up reality. But hey, in the end there is nothing we can do about that. What we can do is to take up the challenge from time to time and put in the effort to get a glimpse into something so much larger than us.
Even if we will never get to the bottom of it.