The End of Smallpox

Derrick Baxby looks at the history of the smallpox vaccination, how it was opposed by many, and how the disease was finally eradicated.

Drawing accompanying text in Book XII of the 16th-century Florentine Codex (compiled 1540–1585), showing Nahuas of conquest-era central Mexico with smallpox.Anyone asked to define ‘conscientious objector’ would undoubtedly describe someone refusing military service on religious or moral grounds. However the term entered English Law in 1898 to describe those who risked fines and imprisonment for refusing vaccination for their children. We now refer to measles and polio vaccines and the prospect of AIDS vaccines as a matter of course, but a hundred years ago there was only one common human vaccine – that for smallpox – introduced in 1798 by Edward Jenner (1749-1823). In 1967 smallpox was targeted for eradication, an achievement officially certified in 1980. The surviving stocks of the smallpox virus are scheduled for destruction this year. This, then, is perhaps an appropriate moment to examine the varied impact, particularly in Britain, of what Macaulay called ‘the most terrible of all the ministers of death’.

By the seventeenth century the pustular disease known as smallpox (so called to distinguish it from the ‘Great Pox’ – syphilis) was sufficiently familiar for its impact to be assessed. Plague was feared, but occurred in Britain only occasionally; smallpox was always present. In the words of Macaulay,

tormenting with constant fears all whom it had not yet stricken, leaving on those whose lives it spared the hideous traces of its power, turning the babe into a changeling at which the mother shuddered, and making the eyes and cheeks of the betrothed maiden objects of horror to the lover.

Smallpox infected most individuals in populous areas eventually and killed 20 per cent or more. It was particularly severe in city children, killing one in three. The disease was spread to close contacts by air and not by vermin or contaminated water, so, although common in overcrowded conditions, it was not necessarily a disease of poverty or ignorance and attention has always focused on its famous victims. Smallpox was particularly evident in the family of Charles I and, through the death of Queen Anne’s heir, William Henry, Duke of Gloucester aged eleven, ended the Stuart dynasty. Other royal victims included Joseph I of Austria, Louis I of Spain, Peter the Great and Louis XV. Prominent survivors included Elizabeth I, Louis XIV, Mozart and Abraham Lincoln who was incubating smallpox when he gave the Gettysburg Address.

Survivors were usually left scarred and as a result it became obvious that second attacks were very rare. This provided the first clue to prevention. In the 1700s Europeans in contact with the East learned that natural smallpox could be prevented by inducing deliberate infection, via the skin, which was often less severe. Introduced into Western society in 1721 by Lady Mary Wortley Montagu who had seen it in Constantinople, the method was called ‘inoculation’ from the horticultural analogy; in oculum – grafting a bud (‘eye’) onto another plant. For reasons still not fully understood, inoculated smallpox tended to be less severe, killing on average one in 200. Faced with the virtual certainty of catching severe, natural smallpox, many risked inoculation and successful inoculators became rich. For example, in 1768 Thomas Dimsdale visited Russia to inoculate Catherine the Great and was awarded £10,000, a barony, and an annuity of £500.

Although particularly useful when epidemics threatened, smallpox inoculation could still sometimes kill (George III’s son Octavius died following inoculation in 1783), while the mildest inoculated case could transmit fatal infection to other contacts. A safer alternative was needed. This was provided by Edward Jenner. Jenner is often regarded as a simple county doctor. However, he was well trained by the great surgeon John Hunter and was elected Fellow of the Royal Society in 1789 for demonstrating the murderous habits of the newly-hatched cuckoo. By the mid-1790s he was a well-respected physician and surgeon with a country practice in Berkeley and a consultant practice in fashionable Cheltenham.

Jenner’s claim to fame is that he first proved the idea that smallpox could be prevented by inoculation with cowpox, a safe related animal agent (or virus). Unfortunately he also claimed that protection was lifelong which proved to be untrue. There was a country tradition that those that recovered from cowpox, a mild disease with localised sores at the site of infection, did not catch smallpox. Jenner investigated the theory and collected circumstantial evidence that supported it. In 1796 he ‘inoculated’ James Phipps with cowpox material from the hand of Sarah Nelmes. Six weeks later Phipps was ‘challenged’ by smallpox inoculation which he resisted. Jenner did more successful cowpox inoculations and published his famous Inquiry in 1798. To avoid confusion, cowpox inoculation was soon called ‘vaccination’ (from vacca, meaning cow) and smallpox inoculation was termed ‘variolation’ (from variola, the clinical term for smallpox).

Information about vaccination spread rapidly. Ironically, it was accepted earlier on the Continent than in Britain where fierce opposition continued into the twentieth century. To some extent vaccination was introduced too early; the germ theory of infectious disease had not been proved, nor laboratory methods developed. Even so the arguments of many opponents persisted into the twentieth century unaffected by developments in medical science, and in many cases defying simple logic.

Jenner made his work freely available, which antagonised some variolators who saw the loss of a lucrative monopoly. Others saw Man, created in God’s image, separate from the ‘brute animal’ and objected to inoculation of ‘foul blood of a diseased brute’. Yet others held that smallpox had its legitimate place in containing populations, was ‘a remedy for wrong’, or ‘a providential method of cleansing the system’.

However, there was legitimate concern about the safety and efficacy of vaccination. Initially it was important to obtain material from genuine cowpox rather than from superficially similar conditions. However, vaccine was then maintained arm-to-arm: individuals were vaccinated from the pustule of someone vaccinated a week earlier. Thus quality control was impossible. Sometimes vaccine lost its potency, due to contaminating bacteria which caused a reaction. This, unrecognised at the time, could result in boils, erisypelas, impetigo and occasionally syphilis; some extremists even claimed that vaccine itself caused syphilis. Also, evidence was accumulating that vaccination did not produce lifelong protection as Jenner had claimed, and that re-vaccination would be necessary. ‘Sanitarians’ who opposed vaccination believed any reduction in smallpox was due to improvements in housing, sanitation etc. which were reducing the impact of ‘filth diseases’ such as cholera and typhoid.

Smallpox epidemics persisted during the nineteenth century, sometimes occurring on a large scale, such as that in 1870-72 with 42,200 deaths suggesting 200,000 or more cases. Proponents of vaccination saw these as evidence of its need, opponents as evidence of its uselessness. In an era of social reform emphasis was increasingly placed on individual choice. However, the medical establishment saw a unique opportunity to control smallpox by legislation. This led inevitably to a struggle between freedom of the individual and state intervention which lasted over sixty years. The 1840 Vaccination Act outlawed variolation and provided for free infant vaccination – the first free medical service in Britain. By 1871 successive Acts made vaccination compulsory and compelled Boards of Guardians to enforce it, with repeated fines for the same child; in default parents could have goods seized and be imprisoned.

Anti-vaccination societies proliferated; by 1889 there were 111 publishing newsletters and organising protests. Some opponents had legitimate fears and some pro-vaccinationists were unhappy about repeated fines, but inevitably various elements sheltered under the anti-vaccination banner ‘…faddists, crotcheteers, fanatics, Home Rulers, Trade Unionists, Socialists, teetotallers…’. Others who spoke against it included A.R. Wallace, co-founder of the theory of evolution (‘vaccination, a giant delusion… never saved a single life’), George Bernard Shaw (‘a particularly filthy piece of witchcraft’), homeopaths, anti-vivisectionists and many sanitarians. Their leading medical supporter was the learned Charles Creighton, who thought Jenner a charlatan and who never accepted the germ theory. The pro-vaccination movement was led by government experts, the most eminent being Sir John Simon, successively medical officer to the General Board of Health, the Privy Council and the Local Government Board.

During the 1870s opponents of vaccination sought election as Guardians and when in a majority on the Board refused to implement the Act; for this ‘the Keighley Seven’ were arrested and imprisoned in York Castle in 1876. Pressure increased in the 1880s. Leicester had a policy of controlling smallpox by isolating cases, rather than routine vaccination. By March 1885, when over 3,000 were awaiting prosecution, a mass rally there was attended by over 20,000 protesters; a figure the organisers claimed as 100,000.

Attempts to repeal the 1871 Act failed and protest continued. A key event was Creighton’s article opposing vaccination in the 1888 Encyclopaedia Britannica. In 1889 the government set up a Royal Commission to investigate all aspects of vaccination; its final report appeared in 1896. The majority of Commissioners concluded that vaccination prevented smallpox or reduced its severity; re-vaccination was beneficial; sanitary measures alone were insufficient; vaccination itself was safe, though dangers from contamination existed; arm-to-arm vaccination should be replaced by animal vaccine; most controversially, compulsion should be retained as a principle. A small minority maintained that vaccination was dangerous and ineffective. All criticised repeated punishments and suggested exemption from vaccination for those with sincere objections.

The Commission’s findings led to the 1898 Vaccination Act which outlawed arm-to-arm vaccination. It also included the exemption clause, thus introducing the concept of conscientious objection into English law. The vaccination lobby saw this as a battle lost; opponents as a battle only half won. The use of vaccine produced in animals aroused old prejudices and increased support from anti-vivisectionists. Also, objectors had to convince magistrates of their sincerity before exemption was allowed.

Pressure was maintained until the 1907 Vaccination Act, through which vaccination was still theoretically compulsory, allowed exemption on a simple declaration. By 1939 only about 34 per cent of children were vaccinated, and the idea of compulsory vaccination was finally abandoned with the introduction of the NHS in 1948. Routine smallpox vaccination in Britain was discontinued in 1971. It is difficult to assess the effect of the various Acts because increased public health measures helped to control smallpox. However careful analysis indicated that it was less common and less severe in the vaccinated. In the twentieth century virulent smallpox (variola) was replaced naturally in Britain by a milder type (alastrim), antigenically identical but with a much lower mortality (1 per cent). This was then gradually eliminated by increased attention to isolation and contact tracing. However both types were occasionally imported, as for example in 1961-62 when five variola importations caused sixty-two cases and twenty-four deaths. Concern was caused by a laboratory-associated outbreak with four cases and two deaths in London in 1973 and this led to the body of legislation in 1974 which now controls safety at work and leisure.

The elimination of smallpox from Europe and North America prompted the World Health Organisation (WHO) to mount a campaign in 1967, when there were 10-15 million cases annually, to eradicate smallpox globally. Smallpox was an ideal candidate for eradication; good immunity followed an attack and the virus was antigenically stable (unlike influenza); there were no carriers (unlike typhoid) or animal reservoirs (unlike malaria); there was a good vaccine. Also, epidemics developed slowly, allowing control measures to be implemented.

Contrary to popular belief smallpox was not eradicated by mass vaccination. Though tried initially it proved difficult to implement in many countries and was abandoned in favour of surveillance-containment. This involved trained workers searching for cases, with rewards for those who found them. Cases and their contacts were then isolated; contacts were vaccinated. Interestingly this strategy incorporated elements of a system devised in 1778 by John Haygarth in Chester. The last natural case occurred in Somalia in 1977 and after exhaustive enquiries the 1980 WHO Assembly concluded that smallpox had been eradicated.

Now the only officially remaining stocks of smallpox virus are in the USA and Russia and are due for destruction this year. That will end the story of smallpox. A disease which killed millions, shaped dynasties, was the first to be controlled by immunisation, the first to be eradicated; which introduced the concept of consciencious objection and health and safety legislation. In the 1880s Louis Pasteur suggested that the term ‘vaccine’ be extended to cover immunising agents being developed by newly-introduced laboratory technology. This has happened, but vaccine’s original meaning and purpose and the disease it helped to eradicate still deserve to be remembered.

Derrick Baxby is Senior Lecturer in Medical Microbiology, Liverpool University, and author of Jenner’s Smallpox Vaccine (Heinemann, 1981).