Smallpox Eradication: Combining Technological and Strategical Innovation

After Jenner demonstrated cowpox’s efficacy in protecting humans from smallpox in 1796, more focused attempts were made to eliminate smallpox on a regional scale. In 1853, smallpox vaccination was made compulsory in Britain. The United States too made smallpox vaccination mandatory. By1914, the smallpox incidence had sharply decreased in most industrialized countries.

Post-World War II, the World Health Organization had been established with the mandate of attainment of highest possible levels of health by all people. The earliest extensive efforts to eradicate smallpox were made in 1950 by the Pan American Health Organization (PAHO).  The campaign was successful in eliminating smallpox from most American countries except for a few. However, the situation in the African and Indian subcontinents never allowed the advanced countries to be free of the smallpox fear. In 1967, the World Health Organization intensified the global smallpox eradication efforts, allocating $2.4 million annually to the effort and the Smallpox Eradication unit, was formed.

To eradicate smallpox, a strategy of both isolation and containment was adopted. Surveillance held the key to success. Any reported outbreak was stopped from spreading, by isolating the individual and vaccinating those who lived in the neighbourhood. Initially, many of the cases were not reported and this came in the way of achieving total eradication. However it must be borne in mind that the smallpox virus does not have carriers and this fact played a significant role in the disease’s eradication. WHO established a network of consultants, who assisted countries in setting up surveillance and containment units. Many of the developing countries also started producing the vaccine themselves. Concerted efforts were made in countries like India where the National Small Pox Eradication Programme received, technical, financial, administrative and political support, which was negotiated by the likes of David Henderson.

By the end of 1975, smallpox persisted only in the Horn of Africa. In countries like Ethiopia and Somalia, where the infrastructure is poor and famines and war were recurrent phenomena, the task was even more difficult and an intensive surveillance and containment and vaccination program was undertaken in the spring and summer of 1977.

After intense verification the global eradication of smallpox was certified on 9 December 1979. The World Health Assembly declared solemnly that the world and its peoples have won freedom from smallpox, which was a most devastating disease sweeping in epidemic form through many countries since earliest time …..

 

 

 

 

 

 

 

 

This 1980 photograph, taken at the CDC, shows three former directors of the Global Smallpox Eradication Program as they read the news that smallpox had been globally eradicated.

If one were to undertake a post-mortem of what contributed to the success of smallpox eradication, various factors could be identified.

Getting innovative with strategy

Though mass vaccinations worked in many countries, in the densely populated countries of Asia, it had to be combined with surveillance and containment.

“A 1966 outbreak in Nigeria started the evolution of a new strategy. In Western Nigeria, where over 90 percent of the population had been vaccinated, another smallpox outbreak had occurred, apparently originating in a religious group which had resisted vaccination. Vaccine supplies were delayed, forcing program staff to quickly locate new cases and isolate infected villages which could then be vaccinated with the limited supplies. A reporting network using the available radio facilities was established to locate new cases. Containment teams moved swiftly to isolate infected persons and to vaccinate susceptible villages. The Nigerian experience demonstrated that an alternative strategy of surveillance and containment could break the transmission chain of smallpox, even when less than half the population was eventually vaccinated (Hopkins 1989).”

 

 

 

 

 

 

 

 

 

 

 

 

 

Fighting Small Pox in Niger, 1969 (CDC/WHO): Credit: CDC/Dr. J. D. Millar [via pingnews].

Description: Photograph made during Smallpox Eradication and Measles Control Program in Niger, W. Africa, February, 1969. In 1979, the World Health Organization (WHO) declared the global eradication of smallpox, and recommended that all countries cease vaccination.

This was followed by a major epidemic in Gulbarga, Karnataka in southwestern India, where the efficacy of the surveillance-containment approach was further reinforced.

“The initial definition of the problem as mass vaccination was a classic symptom of a confusion between ends and means. The goal of the program was the complete eradication of smallpox, and mass vaccination was a means to achieve that end. With the epidemiological experience available in 1966, the choice of mass vaccination as a strategy appeared rational. National governments also favored mass vaccination partly because it was a highly visible display of government action, and partly because of the substantial investments already made in creating the vaccination infrastructure (including jobs and salaries). Fortunately, the smallpox campaign learned quickly from its experiences in Nigeria, India and elsewhere and was able to recast the problem and evolve a new surveillance-containment strategy through experimentation and innovation in the field.”

Large-scale vaccination necessitated high volume production of potent, reliable vaccines. The vaccines had then to be safely and inexpensively distributed and administered.   Major technological innovations, trained human resources and institutional commitment made this possible. The most important contributory factors included:

1. development of the capacity to mass produce high quality freeze-dried vaccine in many countries. The new freeze-dried vaccine greatly eliminated the risk of contamination that was likely with the earlier liquid vaccine. To ensure vaccine quality, WHO established two regional vaccine testing centres in Canada and the Netherlands. Within a few years, several countries achieved self-sufficiency in vaccine production.”
   
   
2. development of the jet-injector, which made vaccination, safe and efficient. The traditional vaccination technique employed a rotary lancet or needle, which sometimes caused serious injury to the vaccinees. The scratch method was replaced by the new injector, though it proved too expensive for house-to-house vaccination in densely populated countries.
   
   
3. invention of the bifurcated needle. “The new freeze-dried vaccine required a different method of presenting single doses of the vaccine. Because the vaccine had to be reconstituted each time and dispensed in tiny quantities, the traditional method of storing liquid vaccine in capillaries was no longer tenable. By 1968, the bifurcated needle had replaced traditional methods in most countries, and by 1970 it was in use everywhere.”
   
   
4. motivated and committed staff, who constantly innovated in the field and came up with simple but extremely useful tools like smallpox recognition cards, watchguards, rewards, rumor registers, and containment records all came from fieldworkers. practical experimentation in the field. New techniques or improvements of existing procedures were then disseminated through surveillance newsletters and periodic review meetings.
   
   
5. staff training was crucial to the success of the entire endeavour.  In fact,  in India, the training programme included  simulation exercises. Make-believe scenarios were created and staff had to respond to the demands of the situation. One involved an infectious disease hospital as a source of infection. ‘Academic epidemiologists were incredulous, but realized when they reached the field that poorly guarded hospitals were notorious for spreading the disease they were trying to control. In the second exercise, the trainee played the role of the chief of a state smallpox program who had to watch against infection from neighbouring areas, investigate sources of infection, and make sense of conflicting reports. Following the exercises, the entire training group then went out to a nearby village with a chickenpox outbreak and proceeded to vaccinate and contain the infection. The field training was highly practical and was conducted not by a ranking administrator but by a junior paramedical assistant who had intimate knowledge of village-level epidemiology.’

The WHO strategies were adapted to meet local requirements and therefore the programmes differed from country to country. Targets were set for mass campaigns and independent appraisals carried out, which primarily involved determining populations

with the vaccination scars. Standards were also set for containment and surveillance. This was supported by allocation of resources like gasoline, jeeps, staff etc. based on categorisation of the sit. Often, established procedures had to be short-circuited and hierarchy ignored to ensure administrative responsiveness.
The common belief is that the smallpox eradication programme succeeded because rules were broken and those involved thought out the box. ‘Hopkins (1989) recounts how one WHO official commented that if the India campaign were successful, he would "eat a tire off a jeep." When the last case was reported, Donald Henderson, director of the smallpox program, sent that person a jeep tire.’
The last case of smallpox was reported in Somalia in 1977. The passion, commitment and concerted efforts had made it possible—smallpox was finally eradicated. It was thought to be as much a triumph of management as of medicine.