Smallpox

V

The Eradication of Smallpox

In 1967 the World Health Organization (WHO) launched a worldwide vaccination campaign against smallpox. At the time, about 10 to 15 million cases of the disease occurred each year, with more than 2 million deaths. Initially, the effort consisted of mass vaccinations, with the aim of inoculating as many people as possible. In Africa, for example, an estimated 100 million people in 22 nations received smallpox vaccine from 1967 to 1969.

WHO experts were dismayed, however, when smallpox outbreaks continued to occur despite the vaccination program. A new plan of attack was called for. After studying statistics and patterns of outbreaks, WHO officials overseeing the vaccination program noted that smallpox epidemics did not tend to cover wide areas all at once. Instead, separate 'islands' of infection seemed to proceed from place to place. With this observation in hand, WHO experts changed their campaign from one of mass vaccination to what came to be called surveillance and containment. Whenever an outbreak was reported, health-care workers would descend upon the area, vaccinating everyone within 5 km (3 mi) or more of the location and making sure that infected persons remained isolated (a procedure known as quarantine.) Often workers would go from house to house seeking smallpox victims. This tactic imposed a defensive ring during an outbreak and kept the virus from escaping to nearby areas.

Two technological innovations aided this campaign. One was a process that freeze-dried the vaccine so that it could be transported easily and would remain potent even in the most extreme climates. The other was a special bifurcated (two-pronged) needle. Unlike the syringes and hollow needles used in other vaccinations, the bifurcated needles could be used in any setting by personnel who required no advanced medical training to perform vaccinations. A health-care worker simply dipped the bifurcated end of the needle into a vial of vaccine to collect one drop of the medicine between the two prongs, before repeatedly scratching the needle across the skin hard enough to break the skin and deliver the proper dosage. Made of stainless steel, bifurcated needles could be easily sterilized and reused, an advantage in areas with limited medical supplies.

With these tools, WHO closed in on smallpox. During the campaign in India during the early 1970s, for example, more than 200 WHO experts oversaw the efforts of thousands of local health-care workers. Occasionally local conditions required creative solutions. In India, homeless people who wandered from village to village posed a possible threat in spreading infection. To help enforce quarantine during outbreaks, officials set up centers where homeless people received food and shelter. Similar steps were taken with nomadic tribes in Somalia who were induced to remain in isolation centers by receiving plentiful food provided by specially hired cooks.

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Within just a few years, WHO’s effort began recording victories over smallpox. In 1962 more than 17 nations in Africa and Asia reported smallpox as a significant health threat. But by 1971, four years after WHO’s vaccination program began, only four nations were reporting smallpox cases. By 1972 the disease was gone from South America. By the next year, having been driven from Indonesia and other Asian nations, smallpox existed only in the Indian subcontinent and a few African nations. By 1975 a girl in Bangladesh recovered from the last case of smallpox recorded in Asia. In 1977 a young man in Somalia had the last naturally occurring case of smallpox recorded in the world. In 1979 WHO declared victory when it announced that naturally occurring smallpox had been wiped from the face of the Earth. The United States halted required smallpox vaccination in 1972 and most other countries worldwide followed suit in the two decades that followed.

VI

Current Status

Today the smallpox virus exists officially in only two laboratories, at the United States Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, and at a virology laboratory located outside Novosibirsk, Russia. For many years WHO officials debated whether or not to destroy the remaining laboratory stocks of the virus. Some argued that all stocks of the virus should be destroyed in order to free humanity from smallpox's shadow forever and eliminate the threat of the virus falling into the wrong hands. Others maintained that the virus should continue to be studied—for the insights that it would provide into viruses in general, and for knowledge that would help fight the disease in case of a future outbreak. In early 2002 the executive board of WHO voted against destroying the remaining stocks of smallpox virus so that scientists can continue research on the virus.

Many experts believe that nations such as Iraq and North Korea may have acquired stocks of smallpox virus that they intend to use as biological weapons (see Chemical and Biological Warfare). Some experts fear that, in addition to the threat from belligerent nations, a terrorist or extremist group might illegally gain access to stocks of smallpox virus and release it into the air in aerosol form in a crowded public place, such as an airport. The effects of such smallpox exposure would be devastating—with the halt of regular smallpox vaccinations worldwide, many people have no immunity to smallpox.

With the intentional distribution of anthrax through the United States mail in 2001, government officials became even more concerned about the threat of smallpox as a bioterrorist weapon. In December 2002 U.S. president George W. Bush announced a plan to protect Americans from the threat of smallpox attack from terrorists or hostile governments. The plan called for state and local governments to form volunteer smallpox response teams made up of people who, in the event of an attack, will implement emergency mass vaccination programs, investigate and evaluate suspected cases of smallpox, and initiate measures to control an outbreak. Health-care workers and other members of the teams will be asked to volunteer to receive the smallpox vaccine. This will ensure that team members can vaccinate others without fear of becoming sick themselves and provide critical emergency services in the days following a smallpox attack.

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