The Global Battle Against Infectious Disease
The End of Plagues
The Global Battle Against Infectious Disease
Palgrave Macmillan 235pp £17.99
‘Smallpox filled churchyards with corpses and disfigured those it did not kill, turning babies into changelings and rendering the maiden an object of horror to her lover’, wrote Thomas Macaulay in 1848. Around the middle of the 17th century smallpox replaced bubonic plague as the most fatal and feared disease. Indiscriminate in its attacks, the ‘speckled monster’ was as likely to infect the rich and powerful as the poor and weak; its victims included Queen Mary of England (1662-94) and Louis XV of France (1710-74). The smallpox story, punctuated by the discoveries of inoculation and then vaccination, which eventually led to its global eradication by 1980, is at the heart of Rhodes’ engaging and expansive exploration of humankind’s quest to defend itself against disease. If our species’ time on earth was represented by a single day we would know about germs only in the last two minutes, he notes. Yet the discovery in the second half of the 19th century that infectious diseases are caused by germs that are specific to each disease has proved one of history’s most significant medical breakthroughs.
Medical control over smallpox started in the 1700s, when variolation, better known as inoculation, was introduced to Britain by Lady Mary Wortley Montagu. Living in Constantinople as wife to the British ambassador, Lady Mary observed how local women transferred small amounts of material from someone with a mild case of smallpox to a healthy infant. Inoculation was an ancient practice across Africa and Asia; it produced a mild infection but conferred lifelong protection. Lady Mary vigorously promoted the practice and gained influential supporters, including the British royal family, and the practice spread across Europe and America. Over time the risks versus benefits of inoculation were established, with a chance of death in 1:50 inoculations compared with 1:5 cases of smallpox. This was much improved on by Gloucestershire doctor Edward Jenner’s experiments with cowpox, a cattle disease closely linked to smallpox. Initially, Jenner had problems persuading the London medical elite of the vaccine’s efficacy and the need for pure cowpox samples but, once convinced, vaccination was taken up worldwide. Vaccination became pivotal to public health efforts but it provoked strong opposition, particularly to compulsory vaccination programmes. British opponents included Alfred Russell Wallace, co-originator with Charles Darwin of the theory of evolution by natural selection, who argued that vaccination probably caused more mortality than smallpox; George Bernard Shaw recoiled from vaccination as ‘a particularly filthy piece of witchcraft’. Our contemporary dissent about the risks of vaccination, such as against measles and the MMR vaccine, has its roots in these arguments.
Inoculation and vaccination originated from individual observation and experimentation but the global eradication of smallpox required a cast of thousands. It was, affirms Rhodes, one of the greatest collaborative human endeavours, which required ‘vast teams of people joined in the endeavour who speak scores of different languages, subscribe to different values, worship different gods, come from almost every culture, and are united only in the global task’. Rhodes justly regards smallpox’s eradication as a modern medical triumph. Other chapters recount global efforts to eradicate polio and diseases such as malaria, tuberculosis and HIV-AIDS. Throughout, his perspective as a trained immunologist offers illuminating insights into the successes and the challenges of immunology and vaccination.
Yet we cannot forget that disease prevention and eradication is a dynamic and highly contingent enterprise. Smallpox retains potency as a potential source for biological warfare. Global human immunity has now weakened to such an extent that populations are as vulnerable to its powers as the Aztec nation of five million that was devastated by smallpox in 1521. The keeping of stores of the virus in American and Russian laboratories generates intense controversy as to whether the existence of supplies increases the risk of the creation of biological weapons, or provides a necessary source for responding to potential attacks. The battle is by no means fought and won.
Stephanie J. Snow is author of Blessed Days of Anaesthesia: How Anaesthetics Changed the World (Oxford University Press, 2008).