Ali Maow Maalin Survives the Last Endemic Smallpox Case

World Health Organization Declares Smallpox Eradicated

Photograph

By: Anonymous

Date: 1979

Source: "Last Endemic Smallpox" Bettmann Collection. Corbis Corporation.

INTRODUCTION

The World Health Organization (WHO) played a major part in the global eradication of smallpox by coordinating an international vaccination effort that led to the absence of the disease in humans. The role of the WHO was especially important in remote areas with poor infrastructure and inadequate health care facilities that often lacked medical personnel capable of delivering the vaccines.

Smallpox, or variola virus, is an Orthopoxvirus and a member of the Poxviridae family of viruses. Smallpox has two main forms, variola minor and variola major. The two forms of smallpox varied in the mortality they caused. Variola minor resulted in death in only about 1 percent of cases, while variola major was fatal about 40 percent of the time. Variola major caused four subtypes of the disease, ranging from a relatively mild form of smallpox to the severe form that often leads to hemorrhaging (uncontrolled bleeding) and death.

Despite the existence of viruses that are closely related to smallpox, such as cowpox, camelpox, and monkeypox, there is no animal reservoir of smallpox. Close contact with an infected person is usually necessary for smallpox transmission, as smallpox is spread by saliva droplets containing the virus. There are also no carriers of the disease that are without symptoms. These characteristic factors made the job of eradicating smallpox more straightforward than controlling other more easily transmitted viruses, such as influenza.

Smallpox requires seven to seventeen days to incubate. This symptomless and non-infectious stage is followed by the onset of flu-like symptoms, usually accompanied by high fever. After two to three days, fever decreases and a rash appears, first in the mouth and tongue, then on the face. Over the next three days, the rash becomes raised bumps filled with pus (vesicles), which later develop into typical bellybuttonshaped vesicles. These then give rise to firm pustules. Over the following days, pustules eventually form crusts and become scabs, which then heal and fall off, leaving pockmarks. A person with smallpox remains infectious until the scabs clear.

Smallpox has taken the lives of millions of people throughout history. Its victims are estimated to number 300 million in the twentieth century alone. People with smallpox who did not die were often left disfigured with pockmarks. Another common complication of smallpox was blindness. Smallpox epidemics ranged across the social strata. Along with millions of common citizens, Queen Mary II of England (1662–1694), King Luis I of Spain (1707–1724), Tsar Peter II of Russia (1715–1730) and King Louis XV of France (1710–1774) all died of smallpox.

The variola virus most likely originated in Africa. Evidence of smallpox has been found in ancient Egyptian mummies and in descriptions of apparent outbreaks of the disease. From Africa, smallpox spread to India and China with traveling traders. During the eleventh and twelfth centuries, it came to Europe with returning crusaders. The Americas were free of the virus until the arrival of European settlers in 1500s. The death toll from smallpox in Mexico alone (mostly among natives) is estimated to be ten million during the first ten years of Spanish rule.

In the Middle Ages, there was no prevention against the disease in Europe. Measures to control the spread of smallpox consisted of isolating the sick and burning their clothing and personal effects. In Africa, China, and India, however, a form of inducing immunity to smallpox called variolation developed. Variolation relied on inoculating a healthy person with pus isolated from the pocks of a person with smallpox. Variolation was usually followed by a mild form of smallpox, which prevented a serious case of the illness. However, people inoculated by variolation were infectious for some time, and there were cases of death as a result of variolation and ensuing smallpox. Despite the drawbacks, variolation was the first active preventative measure taken against the disease.

Variolation remained common outside Europe for centuries, and was introduced to Europe and North America in the 1700s by the English writer and socialite Lady Mary Wartley Montagu (1689–1782), who herself suffered from smallpox. In 1796, British physician Edward Jenner (1749–1823) used cowpox virus to induce immunity against smallpox. His invention arose from the observations he made during a smallpox outbreak in Gloucestershire, England, in 1788. Jenner noted that people working closely with cattle, especially dairymaids who contracted the milder disease cowpox, were not affected by smallpox. Jenner used material from the pocks of a dairy maid's hand to test his vaccine on an eight-year-old boy, who later demonstrated immunity to smallpox.

Despite initial resistance by the medical community, the discovery led to the inoculation of over 100,000 people by beginning of the 1800s in England. After Jenner published his findings on vaccination against smallpox, the practice spread to the European continent and to the Americas, and the first mass inoculations began. Although the numbers of cases in Europe then decreased, there were endemic (naturally occurring) areas in Africa and Asia where the virus was spreading.

At the eleventh World Health Assembly (WHA) meeting in 1958, the Soviet Union delegation proposed the goal of eradicating naturally occurring smallpox throughout the globe. It took until 1967, however, for the WHO to finally launch an intensified eradication program. The program involved setting up regional WHO offices and teams of vaccinators, along with surveillance officers and volunteers to gather data. Teams vaccinated people in the areas immediately surrounding outbreaks first, and then expanded the vaccination target areas outward. In the remote areas in particular, rewards were offered to people who reported cases of smallpox to health workers. Persons in developed countries routinely received smallpox vaccinations, usually in childhood.

In all, over 200,000 people worked on the smallpox eradication effort worldwide. The estimated cost was about 300 million dollars, and over one billion doses of vaccine were administered. The mass inoculations were initially performed with a jet injector, which was replaced in 1968 with a bifurcated (two-pronged) needle. The bifurcated needle reduced the amount of vaccine needed for inoculation to only a tiny drop, and could be better administered in the field.

During the early 1970s, individual countries began to report that they were free of smallpox. The last known case of endemic (naturally-occurring) smallpox occurred in Merka, Somalia, in 1977, where Ali Maow Maalin, a hospital cook, came down with the disease. Maalin is shown in the accompanying photograph after he recovered in 1979.

Before the final victory over smallpox was declared, a special system for certification of smallpox eradication was established. The International Commission for Certification, consisting of international teams of public health, epidemiologists (scientists who track disease outbreaks), and virology experts, was established by the WHO. Areas with endemic smallpox were visited by the Commission two years after the last case of the disease was reported, and based on the reports of the regional authorities, issued certificates when an area was declared smallpox free. Officially, the eradication of smallpox was declared at the thirtieth World Health Assembly meeting in 1980, in Geneva, Switzerland.

PRIMARY SOURCE

ALI MAOW MAALIN SURVIVES THE LAST ENDEMIC SMALLPOX CASE

See primary source image.

SIGNIFICANCE

Eliminating smallpox was one of the major public health success stories of the twentieth century. This effort demonstrated that international cooperation on important health issues could be achieved. Moreover, it also demonstrated that it is possible to eradicate an infectious disease with an effective vaccination program, and that vaccination is a useful preventative method in the fight against infectious diseases.

The smallpox vaccine, although highly successful in preventing the disease, showed some side effects. The most common side effects were eczema, mild smallpox-like disease, and in rare cases, encephalitis. Deaths attributed to the vaccine were rare; estimates showed that one death per million was associated with smallpox inoculations. Significantly, not all people can be given the vaccine, especially those with some autoimmune conditions such as eczema, or with weakened immune systems due to illness or immunosuppressive therapy.

As a result of smallpox eradication, routine small-pox vaccination was officially halted in all countries in 1986. Some scientists voiced hesitation about routine vaccination, as claims were made that smallpox could make a comeback, or a similar animal poxvirus could mutate to where it could infect humans. Monkeypox virus infections have been occasionally identified in humans, but cases have not significantly spread.

People who received the smallpox vaccine retain immunity for at least ten years. Even if exposed to smallpox later than ten years after vaccination, a vaccinated person will likely produce fewer viruses and is much less likely to spread the disease. The exact time interval of effective smallpox vaccine protection has not been determined with certainty, but it is clear that since the immunization ceased, immunity against the disease has diminished in the general population.

After the eradication of smallpox, stocks of the virus were retained in six laboratories in China, Holland, South Africa, the former USSR, the United Kingdom, and the United States. These stocks were later reduced to just two, one in Russia and another in the United States. All smallpox virus stocks were scheduled to be destroyed in 1999, however, both Russia and the U.S. refused to comply with the deadline, stating that a small stock should be maintained for future study, including genetic engineering of the smallpox virus. Later, a World Health Organization scientific committee recommended temporary retention of the remaining stocks of the smallpox virus for research purposes, with the eventual goal remaining for their destruction. Those against the retention of smallpox stocks point to the possibility of a laboratory accident that could release the smallpox virus to the public, or to the possibility that smallpox could be used by terrorists as a biological weapon.

Current research is aimed at producing a safer, longer-lasting vaccine using modern manufacturing techniques that will produce immunity even in individuals unable to receive the standard vaccine. Researches working with the smallpox virus also aim to develop new and improved anti-viral drugs.

The WHO also recommended in 2004 that 200 million doses of smallpox vaccine should be maintained by the organization, as well as a supply of bifurcated needles.

FURTHER RESOURCES

Books

Fenner, Frank, et.al. Smallpox and Its Eradication. Geneva: World Health Organization, 1988.

Plotkin, Stanley A., and Walter A. Orenstein, eds. Vaccines. Philadelphia: W.B. Saunders, 1999.

Periodicals

Arita, I. "Can We Stop Smallpox Vaccination?" World Health, no. 5 (1980): 27-29.

Fenner, Frank. "How Can We Be Sure?" World Health, no. 5 (1980): 35-39.

Henderson, D. A. "A Victory for All Mankind." World Health, no. 5 (1980):3-5.

―――――― "Smallpox as Biological Weapon: Medical and Public Health Management." JAMA, no. 22 (1999): 2127-2137.

Web sites

Centers for Disease Control and Prevention (CDC). "Smallpox." 〈http://www.bt.cdc.gov/agent/smallpox/index.asp〉 (accessed September 9, 2005).

Flight, Collette. BBC Science and Discovery. "Smallpox: Eradicating the Scourge." 〈http://www.bbc.co.uk/history/discovery/medicine/smallpox_01.shtml〉 (accessed May, 9, 2005).