The curious thing is that, while as a doctor I sympathise with such sentiments, I cannot entirely agree with them. Counter-intuitive as it might seem, I know that a world without viruses would not be one in which I would care to live. Why do I suggest such a thing? It introduces what might appear to be a contradictory question. Does the existence of viruses really matter to you and to me? I can assure my readers that, contrary to what our primal instincts might suggest, the answer is, strangely, but indubitably, yes!
In his elegant essay ‘The Lives of a Cell’, the late Lewis Thomas drew attention to the fact that we humans are not above the rest of life. In his words, ‘Man is embedded in nature.’ While accepting the fundamental truth in this, I would further extrapolate from it the fact that nature is embedded in humankind. And the nature I am referring to includes viruses. I don’t, however, expect you, my readers, to simply take my word on this. But even the possibility that we humans owe our existence to, and remain dependent on, the very existence of viruses is more than enough to suggest we take the trouble to understand them.
That is what I hope to achieve in writing this book. It is my intention to enable you, my readers, to understand viruses.
In fact, even at a self-interest level, it is only natural that we should feel the need to understand entities that are capable of seriously hurting us. We surely need to know how they might threaten us and our loved ones and what we can possibly do to mitigate this threat. I freely confess that this was my perspective when, as a youthful medical student, I performed my first experiments on viruses long ago. Years later it remained my perspective when, as a busy hospital physician dealing with serious medical emergencies, it was my duty to diagnose and treat many patients suffering from viral infections. But then, during a period of international travel aimed at examining what was actually happening when new ‘emerging viruses’ were threatening entire populations, I discovered that my former perspective was somewhat blinkered in relation to viruses. Here I invite my readers to remove those same blinkers and look beyond the undoubted mischief of viruses to find answers to their behaviour and presence among us.
Key to such understanding is to get to know their strange and extraordinary world. Thanks to the most modern advances in the science of virology, we are now in a better position than ever before to understand that world. We are about to explore what, in scientific circles, is now called ‘the virosphere’, a play on which forms the title of this book.
How could such an exploration be anything other than an odyssey? Viruses circumambulate our world with the speed of a passenger jet, paying no heed to national boundaries, or circumscribing notions of nationality, ethnicity, race or religion. They pay no heed to sex or age, or social class, or indeed any human hubris of fame, celebrity, wealth or power. They are devoid of any sense of justice or morality, so that our social or religiously derived morals prompting concepts of goodness, badness, justice, sin, simply do not apply. Now add to this situation the fact that these threatening entities are, for the most part, utterly invisible, even under the most powerful magnification of the light microscope, making them all the more enigmatic – and perhaps also the more scary. These invisible entities invade not just our tissues and organs, but, to borrow the metaphor from Anthony Hopkins, they step inside the chalk circles of our most intimate and innermost being: the nucleus of our living cells, the repository of our coding DNA.
It is not a bad thing that we should be wary of viruses, but in this exploration we need to rise above mere scare stories. The fact is that the vast majority of viruses in this world – and there really are very many of them – have no mischievous interest in humans. This rather begs a new question: if such viruses are not interested in you and me, what are they interested in?
My purpose in writing this book is to explain what viruses really are, to accurately define them, and from such an understanding to explore their role in our human history and the wider history of our world. I hope to do so in a way that readers, whether they come from a scientific background or have no prior knowledge of viruses, will understand the true importance of viruses to life and to the biosphere. Given such potential importance, how can we possibly get to grips with such minuscule entities? How can we even hope to visualise their quintessentially viral way of life in their complex ultramicroscopic world? As with historic explorations of alien worlds, it might help our exploration if we could avail ourselves of some guide.
I would suggest that there is an obvious guide, one that is entirely apposite, whose perspective has only recently been opened up to us in wonderful detail through the deepest penetration of the living world by the enlightenment of modern scientific techniques. In this new age of ultramicroscopic exploration, we shall be getting up close and personal to the viruses themselves. As we shall discover, viruses really are far more embedded in us, and in the biological and ecological world that we inhabit, than most ordinary folk might possibly imagine.
Only in the last decade have we come to realise that, from its very beginnings, all of cellular life has inhabited not only the visible biosphere – of solid earth, air and oceans – but also a less familiar and invisible virosphere. The viruses that constitute this virosphere are not merely surrounding us, they are within us, both as evolving extrinsic organisms in themselves and as interactive symbiotic entities that are an intrinsic part of our being. We might not be aware of the presence of these minuscule passengers within us from moment to moment, but the passengers are, in their quintessentially viral way, aware of us.
This might seem somewhat daunting, even frightening, to some of us, but there is no need for alarm. They have always been there. It is likely that they preceded any origins of human life on planet Earth, or indeed, going further back, the origins of the mammals, or any animals or plants, or fungi, or, if I am right, even the single-celled amoebae. All that has changed is that the world of virology is coming to understand the role of viruses in the origins and diversity of life, and what might appear incongruous to any notion of viruses being exclusively agents of disease, the health of the biosphere.
For viruses to achieve all this they must surely possess some remarkable properties. For example, they have no means of locomotion yet they move among us: in pandemic forms they effortlessly circulate around the globe. Although they have no sense of vision, hearing, touch, smell or taste, they detect with uncanny precision the cell, or organ or tissue that is their target destination. This they achieve despite the relentless opposition of powerful immune defences designed to prevent this happening; and once arrived, they penetrate the defences of the target cell, break entry through its protective surface membrane, and once inside take over its physiological, biochemical and genetic programming to compel the cell to become a factory for the production of a new generation of themselves.
Welcome to the world of viruses!
It is, admittedly, a very strange world replete with mysteries. It becomes all the more quixotic when we attempt to examine it at the most basic level.
What then are viruses? How do we even begin to define them? What, for instance, is the difference between, say, a bacterium and a virus? While viruses and bacteria are often confused in the minds of ordinary folk, because they cause many of the common infectious diseases, bacteria and viruses are very different entities. Viruses are more difficult to define than bacteria because they are said to occupy a position somewhere between the biological notions of life and non-living chemicals. This has tempted a distinguished colleague to dismiss them as ‘a piece of mischief wrapped up in