Chapter 26 onwards specifically talks about viruses. From that point onward it discusses things like how viruses take over cells, how the body detects them inside your cells, and what your body does about them from there. On page 182 it starts to talk about RNA, which should be very interesting to you because of how the Pfizer COVID vaccine works. In paragraph 2 of that page it says "RNA is a complex and fascinating molecule that fulfills a variety of different and crucial jobs. The one we care about in this context is to act as messengers that relay the building instructions from genes to the protein factories of your cells."

The book goes into great detail about how viruses hijack your cells to replicate themselves and why that eventually triggers an immune response. Basically, the reason why the vaccine is better even though in the end it would hopefully accomplish the same thing is that the vaccine is just RNA. It's not a whole virus that's trying to kill you while your body is trying to create an immune response.

This book isn't just about viruses and goes beyond what is useful to know to help you understand how vaccines work, though. It talks about immune responses to bacteria, as well, for example. It talks about a lot of different things to do with the immune system in a way that makes it relatively easy to understand. For that reason, I'd recommend this book to anyone looking to know more about human immunology in general. Another user on this post very unfairly described Dettmer's approach to teaching as "irreverent" but what he's trying to do is give normal people a basic understanding of these difficult topics. If he went in-depth, this would all go right over the heads of the people it would benefit most to know about this sort of stuff (like myself).

At the end of the day this book is 300-odd pages (with artistic illustrations similar to what you'd find on Kurzgesagt) explaining in layman's terms how the human immune system responds to different types of pathogens.