The Life and Death of Smallpox
by Ian and Jenifer Glynn
288pp, Profile, £17.99
One of the paradoxes of the World Health Organisation's campaign against infectious diseases is that the greater its success in eradicating once-deadly viruses and parasites, the greater their potential to wreak havoc on no longer immune human populations. This is nowhere more true than in the case of smallpox, a virus once familiar to Pepys, Napoleon and the lowliest cowherd but now the exotic preserve of a handful of governments and - if the Pentagon is to be believed - international terrorists.
Eliminated from Europe and North America by the early 20th century and eradicated worldwide by the WHO in 1979, the variola virus or the "pox", as writers from Shakespeare to Thackeray have called it, induced one of the most unpleasant and disfiguring deaths known to man. Within weeks of contracting variola, a patient would break out in hard, raised spots that gradually softened and filled with pus. In two thirds of cases the "pustules" would flatten and scab off. But in the case of "confluent smallpox" the pustules were so numerous that they fused and the mortality rate rose to 60%, while in the rare and most horrific form, "haemorrhagic smallpox", death was virtually guaranteed.
By the late 18th century, smallpox was killing 400,000 Europeans a year, one in 10 of them children under five; however, those who survived enjoyed immunity against further infections with only permanent pitted scars - the pock marks - to show for their ordeal.
That is no longer the case. As Ian and Jenifer Glynn point out in their timely study of the disease, when a traveller from Mexico re-introduced the virus to New York city in 1947, such was the fear of a new epidemic that the authorities vaccinated six million people within a month. So that when, following September 11 2001, fears were raised that bio-savvy jihadists might be planning to release weaponised aerosols in crowded city centres, both the US and the UK began building up their smallpox vaccine stocks.
Thankfully, the threatened attack never came and the Glynns do not go looking for it. Instead, they focus on the history of the disease from antiquity to the present day, taking in the pockmarked mummy of Rameses V, the Spanish conquest of Central America (a victory made possible by the conquistadors' prior exposure to the disease and the Aztecs' catastrophic lack of immunity) and the introduction of the then medico-revolutionary practice of inoculation, or "variolation", to England in the early 18th century.
Apparently, the first person to witness this procedure, which entailed the insertion of infectious viral material from a smallpox victim under the skin of a non-immune patient, was Lady Mary Wortley Montagu, the eccentric wife of the British ambassador to Turkey. Likening it to the "engrafting" of a bud in horticulture (the Glynns point out that the literal meaning of inoculation is "in-eyeing"), Lady Mary had the procedure performed on her own son and in 1717 introduced it to England. But while inoculation, where successful, conferred lifelong immunity, in some cases inoculated patients would develop the full-blown disease and die, or else infect those near to them, increasing the risks for others.
The result was that many educated parents, including Leopold Mozart, father of Wolfgang, actively resisted the new-fangled procedure. Explaining his decision not to inoculate his 11-year-old prodigy when a smallpox epidemic seized Vienna, Leopold wrote: "It depends on His grace whether He wishes to keep this prodigy of nature in the world... or to take it to Himself" (fortunately for mankind, "He" allowed the prodigy to survive).
Edward Jenner, a lowly country doctor and expert on the nesting patterns of the cuckoo, in 1796 improved on inoculation by taking the related cowpox virus from a pustule on the arm of a milkmaid and injecting it into a healthy young boy. Jenner was able to show that vaccination by the cowpox, or vaccinia virus, induced protection against smallpox in a manner that was both safe for the patient and for those with whom he might come into contact. But while this was a major advance - one whose benefits we continue to reap today in the practice of vaccinating against diseases such as measles, mumps and rubella - Jenner spent much of his subsequent career, in the Glynns' phrase, "kicking against the pricks".
Some, like Dr William Rowley, a prominent physician who launched a hysterical campaign claiming that vaccination had produced an "ox-faced boy", were relatively easy to dismiss. But others, such as John Birch, surgeon at St Thomas's Hospital, were not, invoking as he did the cold voice of Malthus that smallpox was "a merciful provision on the part of Providence to lessen the burden of a poor man's family".
Thankfully, today such voices are no longer in the ascendant but, as the recent public concern over the side-effects of the MMR vaccine demonstrate, such worries have not gone away, merely receded. Raised in a world made safe by Jenner, for many the risks of contracting smallpox or some other disease will always seem more remote than the more immediate risks associated with vaccination. Having said that, were the unthinkable to happen and were terrorists to succeed in releasing the variola virus in a major western city tomorrow, I know where I would stand.
· Mark Honigsbaum is the author of The Fever Trail: The Hunt for the Cure for Malaria (Macmillan). His new book, Valverde's Gold: A True Tale of Greed, Obsession and Grit, is published next week.
