Excerpt from Immune by Catherine Carver, plus links to reviews, author biography & more

Yet despite all there is to fear, there is also much to be hopeful about. In'Clever Drugs'( Chapter 16 ) we will end the book with a future-gazing look at a new dawn of drugs that will harness the power of the immune system and save us from the nightmare of the antibiotic apocalypse.

CHAPTER ONE
Full Frontal Immunity:
The First Line of Defence

Staring at a measuring cylinder full of my own pee, I couldn't help but feel the reality of being a Cambridge student wasn't quite how I'd pictured it. I'd definitely imagined less urine and more ancient spires, swarms of bikes and formal dining with Nobel laureates. That class experiment was one of many that showed me the brilliance of our insides (and the desperate lengths a nerd is willing to go to learn). In an era when we spend billions learning about stars trillions of miles away, it's incredible just how little we know about what goes on inside each and every one of us, each and every day. Happily for you, this book offers a collection of curious tales from the immune system without any obligation to harvest your own bodily fluids.

Our story begins with a feat of imagination: if we were to put 100 people in a room, hand them some crayons and ask them to draw a defence system, what might you expect to see? You can have a pretty good guess – probably castles with high, impenetrable walls surrounded by moats (shark-infested, among the more creative participants). Perhaps some soldiers pouring boiling oil on unwanted guests. A less historically inclined artist might draw us an array of lasers, rockets and machine guns. These are relatively predictable because even without knowing what you're defending against, there are certain solid choices you can make. This is akin to the 'innate' arm of the immune system – the set of defences that we are born with, and which essentially remain the same throughout our lives. The innate system is the first line of defence because it's already set up and ready to take on a range of common diseases based on predictable characteristics of the threats to our body. For instance, all invaders need an entry point – it doesn't matter if you're a tiny virus or a massive worm, you need a way in – so part of the innate immune system's role is to have robust control of the body's entry and exit points. Let's imagine a different task. If we had given our 100 people the challenge of drawing a defence system against a very specific threat, they would have drawn rather different defences. For instance, garlic and holy water would be essential in an anti-Dracula defence system, but would be frankly embarrassing in the face of Darth Vader. This opponent-specific weapons selection resembles the 'adaptive' arm of our immune response, which complements the breadth of the innate response by being able to recognise and respond to the specific threat at hand. Thus our arsenal evolves over our lifetime as we build up a memory of all the infections that we have encountered since the day we were born. So my immune system's bag of tricks might not currently include a smallpox solution, but if I were to contract the disease my adaptive immune response would try its hardest to create one to kill the virus before it killed me. However this adapting process takes time. Thus all my innate defences would essentially hold the fort, and in many instances this first line would be enough to wipe out the invader before the adaptive system gets a chance to craft bespoke weaponry. There are lots of connections between the innate and adaptive immune responses, and the more we discover, the more blurred the boundaries between the two appear. For now though, it's a good way of pulling apart the delightfully complex inner workings of the best defence system on the planet: us.

Skin deep
Our first innate defence is hidden in plain sight: skin. Skin is the largest human organ; if you were to peel yours off you'd lose about 12kg (27lb) instantly. Human skin has been used to make wallets and cover books, and if you were inclined to spread yours out flat it'd make a sizeable rug at about two square metres (22 square feet). Perhaps inspired by this thought, a design company has created a range of furniture that mimics human flesh. Each chubby seat is designed to look, feel and, thanks to pheromone impregnation, smell like a hunk of flesh. You can even have a belly button added to it. This may sound strange, but lots of people lounge, snuggle and laze on a genuine sheet of dead-cow skin every evening. Thankfully for the sofa industry they have people much more adept at marketing than I, hence 'leather sofas' not 'dead-cow couches'.

Excerpted from Immune by Catherine Carver. Copyright © 2017 by Catherine Carver. Excerpted by permission of Bloomsbury USA. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.