Edward C. Holmes welcomes a robust account of how viruses emerge and how pandemics can be prevented.
The Viral Storm: The Dawn of a New Pandemic Age
- Nathan Wolfe
Pandemic disease is a world traveller. This simple fact underlies much of the work of the Global Viral Forecasting Initiative (GVFI), an organization established and run by microbiologist Nathan Wolfe, which aims to predict and prevent disease pandemics. So it is apt that I read Wolfe's The Viral Storm on a crowded airliner bound for Beijing, and fortunate that the book was sufficiently diverting to keep me awake for 13 hours. It is an excellent piece of scientific gothic, rich in descriptions of the threat we face from emerging viruses and how we might prevent them from becoming pandemic.
The book is part description of viruses and how they jump species to emerge in new hosts, part autobiography and part advertisement for the GVFI. Wolfe discusses viral natural history and the history of past pandemics, splicing in references to his research trips to the developing world. His clear message is that humans are entering a new pandemic age, fuelled by such factors as the rise in global travel, urbanization, deforestation and changing agricultural practices, all of which increase the likelihood of human exposure to animal species that carry potentially deadly viral infections.
In this connected world, new viruses are able to spread quickly, perhaps with devastating effect. “A storm is brewing,” says Wolfe, and science must retool to meet this pandemic threat. That will mean increased surveillance of potential reservoir species, the deployment of new technologies that can quickly identify the infectious agent responsible for a disease outbreak, and the use of social-networking media to track cases of human infection in real time.
Wolfe's arguments are generally convincing, particularly on the science of viral surveillance and the part that social media might play in this; the next pandemic will doubtless be both televised and tweeted. Yet he overgeneralizes at times — for example, when stressing the role that hunting, by exposing humans to diverse animal species, has in viral emergence. Hunting may be responsible for the emergence of only a small number of human infections — although these include HIV, which ignited the current interest in emerging viruses and may have entered humans through the consumption of infected 'bush meat'. Some overexuberance should be forgiven, as Wolfe has a gift for conveying the thrill of scientific research, writing with both gusto and panache.
His most provocative claim is that it is possible to predict which diseases will emerge in the future. This has been called the holy grail of research into infectious disease, and has attracted considerable research funding. Although 'prediction' is an enticing word, how it will be done is vaguely described at best. In Wolfe's research programme, prediction seems to involve fine-scale surveillance — for instance, through increasingly high-tech surveys of viral biodiversity in potential reservoir species, the monitoring of unusual animal die-offs, and the minute-by-minute screening of Google trends, Twitter and mobile-phone data.
Gathering such data is laudable, but still more reactive than predictive. In reality, accurate prediction faces challenges that could prove insurmountable. A novel virus discovered in a potential reservoir species may not replicate in human cells; a virus that replicates in human cells may not transmit between humans; and a variety of epidemiological processes dictate that even if such a virus is able to transmit between hosts, it may not spread through a population. Predicting viral emergence therefore requires a difficult, and perhaps unattainable, synthesis of genetics and epidemiology.
I believe that this fad for prediction presents a greater danger: that we establish expectations so unrealistic that they are met with inevitable failure, in turn undermining public confidence. Another unwelcome consequence, in my view, is the diversion of research funds from basic biological studies of viral emergence — such as defining the relationship between a virus and its host-cell receptor — to more speculative programmes, such as predicting future viral evolution.
Wolfe has become the public face of emerging disease. This enjoyable, well researched and thought-provoking book shows that he has a clear vision of how pandemics occur in human populations and the part he might play in their prevention and control. Although it is not clear what the coming years will hold, one safe prediction is that Wolfe will have a lot more to say. On the evidence of this book, he is worth listening to.