Smallpox secondary prevention

Eradication

“	The annihilation of smallpox—the dreadful scourge of the human race—will be the final result of vaccination.	”
—Edward Jenner (1749–1823)

Since Jenner demonstrated the effectiveness of cowpox to protect humans from smallpox circa 1796, various attempts were made to eliminate smallpox. In 1842, England banned inoculation, later progressing to mandatory vaccination instead. In the United States, from 1843 to 1855 first Massachusetts, and then other states required vaccination. Although some disliked these measures, coordinated efforts against smallpox went on, and the disease continued to diminish in the wealthy countries. In poorer countries, vaccines and the necessary infrastructure were less affordable and available.

Vaccination during the Smallpox Eradication and Measles Control Program in Niger, February, 1969.

In 1958 the Soviet Union called for the eradication of smallpox from the planet. At that point, 2 million people were dying every year. In 1967, an international team was formed under the leadership of an American, Donald Henderson. To eradicate smallpox, each outbreak had to be stopped from spreading, by isolation of cases and vaccination of everyone who lived close by. This process is known as ring vaccination. The key to this strategy was surveillance and containment. Surveillance can be best defined as the monitoring of cases in a community. The initial problem the WHO team faced was inadequate reporting of smallpox cases, as many cases did not come to the attention of the authorities.

The fact that man is the only reservoir for smallpox infection played a significant role in WHO deciding to eradicate smallpox. There are many other pox viruses in nature, including monkeypox. However, none appears to be of public health significance. In addition, smallpox carriers did not exist.

WHO established a network of consultants who assisted countries in setting up surveillance and containment activities.

Eradicating smallpox required huge effort and concentration of manpower. In India and Bangladesh, religion and civil strife along with natural disasters became obstacles. In fear of offending the goddess associated with the disease, many Hindus refused the vaccine. In some countries, such as the Sudan, civil war threatened to interfere with eradication attempts. Clearly, health teams placed themselves in great danger by working in war-torn areas. Surprisingly, none of the team members were hurt in the process.

Natural events also impeded the vaccination team’s efforts. The monsoon rains burst dams and dikes. The rain and flooding forced people to flee, once again allowing smallpox to spread. This outbreak took the team a whole year to stop.

The last major European outbreak of smallpox was the 1972 outbreak of smallpox in Yugoslavia. After a pilgrim from Kosovo returned from the Middle East, where he had contracted the virus, an epidemic infected 175 people, causing 35 deaths. Authorities declared martial law, enforced quarantine, and undertook massive revaccination of the population, enlisting the help of the WHO and Donald Henderson. In two months, the outbreak was over. Prior to this, there had been a smallpox outbreak in May-July of 1963 in Stockholm, Sweden, brought from the Far East by a Swedish sailor; this had been dealt with by quarantine measures and vaccination of local population.

The last naturally occurring case of Variola Minor was diagnosed in Somalia on a cook named Ali Maow Maalin on October 26, 1977. The last naturally occurring case of the more deadly Variola Major had been detected in October 1975 in a two-year-old Bangladesh girl, Rahima Banu. In the final tally, the U.S. had applied $300 million to the eradication program.

The global eradication of smallpox was certified, based on intense verification activities in countries, by a commission of eminent scientists in December 1979 and subsequently endorsed by the World Health Assembly in 1980.