House on Fire by William H. Foege

enough countries had become free of smallpox that it was clear that the vaccine, if applied correctly, could bring about eradication. However, eradication had so far been accomplished only in wealthy countries and in countries with a low level of smallpox or with smallpox workers who were obsessive in pursuing the program. What remained unknown was whether the same goal could be accomplished in poor countries that had high smallpox rates combined with meager health resources and inadequate infrastructures and communications systems.
    Some people assumed that it could be done, that it was just a matter of addressing the inherent problems of resource-poor nations. Others maintained that smallpox could never be eradicated, and they offered as proof the fact that similar efforts to eradicate malaria as well as yellow fever had failed. Those who believed eradication was possible would point out the difference: unlike malaria and yellow fever, smallpox is entirely dependent on human organisms in its life cycle. The doubters would respond that no disease had ever before been eradicated, and thus it was surely an impossible goal.
    It was in this climate of hope, doubt, and debate that the WHA executive board finally approved a global smallpox eradication project inFebruary 1966. This decision did not come easily. Back in 1958, the Soviet Union had proposed before the WHA a resolution calling for a global effort to eradicate smallpox. The resolution had passed, but little in the way of substantial efforts had followed. At its May 1965 meeting, the WHA again debated the issue. Many countries, including the USSR and the United States, supported the idea, but there was disagreement over how to budget for the program, and once again the delegates passed a resolution with no plan for action. The following year, in 1966, the WHA finally ratified a funded program for global smallpox eradication, to be completed within ten years, and asked WHO to assume the principal role in organizing and coordinating the effort. 2
    There were several reasons why the WHO program had a good chance of succeeding. First, key technological advances made it possible to standardize the quality and stability of the smallpox vaccine worldwide. Up to this time, the production of the vaccine had remained almost a cottage industry in many countries. This meant that while the vaccinia virus—somewhat modified over the years from Jenner’s original cowpox virus—was a great vaccine, it wasn’t consistently great. The potency varied widely. The production process was crude, involving shaving calves, scarifying the exposed skin (scratching or lacerating the skin to make it raw), and painting this raw surface with a substance containing vaccinia virus. The virus would grow on the scarified tissue and then be harvested by raking off the pustular material. The resulting matter was cleaned of extraneous bits of hair and flesh to provide high concentrations of vaccinia virus. It looked as unappetizing as it sounds.
    Much of the resulting vaccine was kept in a liquid form that required refrigeration to remain viable—yet high temperatures were the norm in most smallpox-endemic areas. It was possible to launch effective programs with liquid vaccine, as many areas had shown over 160 years, but it was very difficult. Early in the twentieth century a method was developed for freeze-drying vaccines, permitting them to be stored at room temperature for extended periods. However, there remained the problem of how to convert all the vaccinia manufacturers around the world to this new technology.
    Early in the eradication program, WHO, under the leadership of D. A.Henderson, assembled a panel of experts who came up with a global standard for the vaccine and created a detailed manual for its production as well as how to convert to freeze-drying the vaccine. Consultants were sent out to help countries convert to the new system. Reference centers for testing vaccines were