From 1958 to 1966, the World Health Assembly convened annually to address the eradication of smallpox. Within this timeframe, the WHO made recommendations on the standardization of freeze-dried vaccines and called for industrialized countries to contribute monetary funding and donations of vaccines. By 1964, the WHO Expert Committee on Smallpox defined three phases of the Smallpox Eradication Program:
1. The preparatory phase, including a detailed plan submitted to WHO for consideration
2. The attack phase, with concentration on areas of high population density, whether urban or rural, the goal is 100% coverage; and
3. The control phase, with continuation of the vaccination programme, epidemiological investigation of outbreaks, and “ring” vaccination around outbreaks. Emphasis was placed on close international cooperation and independent concurrent evaluation of the results of vaccination coverage.[xiii]
When the Eighteenth World Health Assembly convened in 1965 the members passed a resolution declaring that the global eradication of smallpox was one of the organization’s main objectives. A couple of years later, the eradication of smallpox became the main effort for the WHO, and collaborating countries aided in eradicating smallpox from twenty-four countries. The WHO reported, “These included 11 countries in Africa, 7 in South America, and 6 in Asia.”[xiv] However, fifty countries remained endemic and mass vaccinations fell short of the eighty percent mark. The World Health Assembly estimated that 1.1 billion people populated the endemic areas that needed vaccines, which meant an unprecedented effort would need to be put forth to vaccinate two hundred to three hundred fifty million people each year for ten years.[xv] A plan of this magnitude required the support of the two superpowers in the world at the time: the U.S. and the Soviet Union.
The Smallpox Eradication Program relied heavily on donations from collaborating countries especially from the U.S. and the USSR to be successful. Dr. Henderson reiterated this point by explaining, “In brief, there is no question that the smallpox eradication programme could ever have succeeded without the collaborative relationships between the USA and the USSR which survived, indeed thrived, through some of the most difficult days of East-West antipathy. It was the WHO venue that made these relationships possible.”[xvi] Therefore, the WHO facilitated the cooperation of both Cold War enemies to aid in the eradication of smallpox. As mentioned earlier it was the Soviet Union that initiated the WHO to seriously develop a program to eliminate smallpox in 1958. Moreover, the Soviet Union donated twenty-five million doses of smallpox vaccine annually while the U.S. pledged fifty million doses annually to countries in West Africa.[xvii] However, Dr. Henderson reported that the Soviet Union vaccine donation amounted to more than eighty percent of all vaccines donated to the WHO.[xviii]
One reason for this discrepancy is that the U.S. had its own smallpox eradication program started by President Lyndon Johnson in November 1965. This was a five-year program to eradicate smallpox and control measles in twenty countries in West Africa. The program was a joint effort by the CDC, which planned the program and provided technical assistance, and the U.S. Agency for International Development (USAID), which provided funding.[xix] In fact, the program started by the U.S. led the collaborating nations in the WHO to vote confidently in a resolution to eradicate smallpox. During the World Health Assembly in 1965, Dr. Henderson explained, “However, the fact that the United States had recently committed to providing all necessary support for smallpox eradication in eighteen West African countries was strong, tangible affirmation of support for the active pursuit of global smallpox eradication.”[xx] The delegates voted in favor for special budget of $51.6 million dedicated to smallpox eradication on a narrow margin.
Surprisingly, the U.S. delegates voted against the special budget even though it was the U.S. commitment in West Africa that drove the other delegates to believe the eradication of smallpox was possible. The outcome infuriated the WHO Director-General Candau especially with the U.S. because Candau did not believe that any pathogen could be eradicated and thought the efforts to do so were futile. Thus, Candau requested from the US surgeon general William Stewart that Dr. Henderson, an American, would be the director of the program so that if it failed the responsibility would fall on the U.S. government.[xxi]
The Smallpox Eradication Program now rested on Dr. Henderson’s shoulders, and he succeeded through cooperation with national governments like the USSR. Dr. Henderson collaborated closely with the Russian delegate, the Soviet vice minister Dr. Dimitri Venediktov. The Soviet Union did not agree that an American should lead the program because it was the Russians who initially proposed to the WHA for an eradication program for smallpox. However, the Soviet Union accepted Dr. Henderson as the director of the program. Dr. Henderson recollected his meeting with Dr. Venediktov where the Soviet vice minister expressed, “We have checked you out, and have favorable reports of your performance at CDC. More than that, we believe that your only goal is that of eradicating smallpox. You have our full support.”[xxii]
Dr. Henderson and Dr. Venediktov bridged together two superpowers in conflict with another to come to one common goal to eradicate smallpox from the world. The partnerships between the two representatives of the U.S. and USSR did not hesitate to aid the WHO to fight against this virus. This is evidenced when the WHO adviser in Afghanistan found the vaccines that Russia donated did not meet the international standards of potency. Dr. Henderson went straight to Dr. Venediktov’s office to address the issue. Once notified, Dr. Venediktov promised all vaccines donated from Russia would meet the international standards, and eventually, they even exceeded the standards in potency and stability.[xxiii]
Additionally, Dr. Henderson and Dr. Venediktov worked together to hire several Russian health workers into the eradication program which proved to be among the best in the field of epidemiology. Overall, the Smallpox Eradication Program recruited 765 individuals from seventy-three different countries as staff members and consultants.[xxiv] In the end, the cost of the Smallpox Eradication program amounted to $313 million. From 1967-1969, the U.S. contributed a total of $26.24 million and the USSR contributed a total of $14.02 million. On the other hand, the USSR donated smallpox vaccines at a total cost of $15.31 million and the U.S. donated only $57,758.[xxv] In short, the Smallpox Eradication Program succeeded through the alliance between the U.S. and USSR, which Dr. Henderson and Dr. Venediktov’s relationship represented.
The Smallpox Eradication Program’s success did not solely rely on the financial support of two superpowers but required a plan and the personnel to implement vaccinations to enough of the population to stop the outbreaks of the virus. The initial plan to eradicate smallpox was a mass vaccination program that attempted to vaccinate eighty percent of the population of a country where it would cause an effect known as herd immunity.
Herd immunity requires a substantial proportion of the population to develop immunity to an infection either through previous infection or vaccination. When a community reaches a high proportion of immunity, such as eighty percent, it disrupts the chain of infection where the disease cannot grasp a foothold to spread amongst the community and lowers the probability for non-immune individuals to encounter an infectious individual. Mass vaccination showed promise because it was the common strategy most prevalent during the 1960s.
Moreover, mass vaccination was credited for the eradication of smallpox in most of the developed world in the Western world and in a few developing countries. The main example of the mass vaccination plan was the case of Indonesia, which eradicated smallpox in the 1930s. Indonesia, as a developing nation, provided an example to show that other developing countries could eradicate smallpox through mass vaccination and a “systematic program of primary and periodic revaccination.”[xxvi] One of the factors that contributed to the success of mass vaccinations was access to freeze-dried vaccine that could withstand storage at 98 degrees Fahrenheit for a month, making it ideal for tropical areas still endemic to smallpox.[xxvii]