Arita, Isao

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176 Environmental ConservationGlobal Commission for the Certification of SmallpoxEradication, certify that smallpox has been eradicatedfrom the world'. It was on the basis of the evidenceprovided in the Final Report of the Global Commission,*which is now in the course of publication by WHO, thatthe World Health Assembly, representing 155 countriesof the world, participated in the historic declaration on8 May 1980.**See top footnote on page 173 and the WHO account follow-ing it; also footnote on page 177.—Ed.Frank Fenner, ChairmanGlobal Commission for the Certification ofSmallpox Eradication, World Health Organization;John Curtin School of Medical ResearchThe Australian National UniversityCanberra City, ACT2601Australia;formerly DirectorCentre for Resource and Environmental StudiesThe Australian National University.Smallpox Eradication: Man's Success in Eliminating a Most Dangerous DiseaseIntroductionIn Egypt in the year 1160 B.C., King Ramses V diedof an acute disease that was characterized by a disfiguringrash. The characteristics and distribution of the rash,which can be seen on the skin of the King's mummifiedbody preserved in the Cairo Museum, are such thatscientists believe he died of smallpox. This may be thefirst physical evidence in the history of medicine thatsmallpox was present in North Africa already more than3,000 years ago.Severe epidemics of smallpox or smallpox-like diseaseswere described in many areas of Africa and Eurasia beforethe 15th century. In the 16th century, smallpox invadedthe Americas, and since the 17th century it has beenrampant practically throughout the world.There had been no known effective control measuresfor this disease until Edward Jenner discovered a vaccinetowards the end of the 18th century. This vaccine hadbeen gradually used in many countries during the 19thcentury and the first half of this present century. Inten-sive vaccination programmes, developed during thisperiod in North America and Europe, helped to stopindigenous spread of the disease in these areas, and thusthe concept of eradication gradually emerged, based onthe realization that the disease was maintained only byperson-to-person transmission. Thus, would it not bepossible to eliminate the disease by giving immunity toall persons through good vaccination programmes? In1958, the Russian delegation proposed a resolution aimedat the global eradication of smallpox to the delegationsat the World Health Assembly, who wholeheartedlyadopted such a resolution. However, progress thereafterwas slow because health services in the zones of endemicsmallpox had only limited resources and were unable todevelop systematic vaccination programmes.In 1967, an intensified global programme for theeradication of smallpox was started on the basis of an-other resolution that had been passed at the session ofthe World Health Assembly which had been held in 1966.This identified the difficulties in programme developmentdue to unavailability of adequate resources in zones withendemic smallpox, and decided that the global pro-gramme should receive funding from the WHO budget aswell as voluntary contributions from developed countries.For the strategy and development of the programme,there were a few important advances that were identifiedduring the campaign as outlined in the next three num-bered sections:1) Improvement of Vaccine QualityWhen the intensified global campaign was organizedin 1967, the World Health Organization (WHO) carriedout an extensive survey to discover whether the vaccinethat was being used in the countries with endemic small-pox really met WHO standards. Surprisingly, the resultsshowed that only 15% of the vaccine batches met WHOstandards. This implied that some 85% of the vaccina-tions that were being administered during the eradicationcampaign throughout the world, were giving incompleteprotection. Urgent action had therefore to be taken.Vaccine samples from all the producers that weresupplying vaccine to the eradication campaign werehenceforth subject to WHO testing, and only batches ofgood quality were used. Intensive consultative workcommenced between international experts and producersin order to improve the method of production, followingwhich a simple and practical manual of the productionmethodology of the vaccine was made available to theproducers by WHO.By 1970, 80% of the vaccine met WHO standardsand, by 1973, 95%. This improvement in the quality ofthe vaccine was the first important contribution to thesuccessful development of the programme.2) From Mass Vaccination to the Surveillance-contain-ment MethodAt the beginning of the campaign, systematic coverageof the population by effective smallpox vaccination wasconsidered to be the essential method for ultimateeradication. However, after two years of the campaign, itwas recognized that this method was unrealistic and in-effective, and for several reasons. First, 100% vaccinationcoverage was a very difficult task to achieve in the areaswhere the functioning of the health services was ex-tremely poor, though it was chiefly in these areas thatsmallpox was continuing. Secondly, even if 80—90% ofthe population was vaccinated, with great effort, the re-maining non-immunized 10—20% of the population wassufficient to maintain smallpox transmission—particu-larly if the areas were densely populated. On the otherhand, epidemiological investigation of smallpox out-breaks showed that smallpox cases were now usuallyoccurring only in a limited number of villages, and thatthe spread of the disease was much slower than had pre-viously been believed.Now the following question arose: the effective andeconomical way to stop transmission would be to identifythe villages where cases were occurring and, instead ofcarrying out mass vaccination campaigns on a large scale,conduct quick and small-scale vaccination programmesto contain the outbreaks in, for example, a particularvillage. In fact this method, termed the 'surveillance—containment method', proved to be more effective thanmass-vaccination programmes in interrupting transmissionhttps:/www.cambridge.org/core/terms. https://doi.org/10.1017/S0376892900007487Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 12:31:20, subject to the Cambridge Core terms of use, available atShort Communications 177of smallpox in West and Central Africa during 1967 to1969. The method was rapidly adapted for the eradica-tion programmes in other regions, such as South Americaand the Indian sub-continent.Despite the important work of MacCallum & McDon-ald (1957), a recent study on the effect of temperatureand relative humidity on variola (smallpox) virus in crusts(scabs) collected from patients, indicated that the virusremains viable in crusts for only a few months in a tropi-cal climate (Huq, 1976). More important, however, arethe epidemiological findings in many countries in differ-ent parts of the world, namely that smallpox has longbeen eradicated from them and that there has been nospontaneous recurrence in them unless it was knownthat the disease had been imported by the patient fromone of the remaining areas of endemic smallpox. As wellas North America and Europe, such areas include Mada-gascar (which has been free from smallpox since 1935),Philippines (free since 1950), Greece (free since 1951),Thailand (free since 1963), and Ecuador (free since 1965).3) Mobilization of World ResourcesMember States of WHO recognized the urgency anddesirability of completing eradication as soon as possible.Accordingly international collaboration between small-pox-endemic and fund-giving countries developed, in ad-dition to the WHO regular budget—thus promoting cashdonations, the participation of international epidemiolo-gists, and engendering free supplies of the vaccine.Forty-six countries, as well as UNEO, UNICEF, UNDRO,and a few private organizations, contributed to the WHOVoluntary Fund for Smallpox Eradication or helped ona bilateral basis, and these donations have totalledUS$111 millions during the last 13 years. More than 700epidemiologists from 70 countries participated in theprogramme as international personnel.AchievementWhen the intensified global programme was started in1967, there were 33 smallpox-endemic countries, includ-ing Brazil in South America, countries in Africa south ofthe Sahara, and others in South-East Asia (including In-donesia). Brazil recorded its last case in 1970 and Indo-nesia in 1971. South-East Asia, which included the small-pox-endemic countries of Bangladesh, India, and Pakis-tan, recorded its last cases in 1975, and the last case inthe world occurred in Somalia in October 1977.Surveillance continued to check 'entire populations'by house-to-house visits which were carried out atregular intervals during at least two years after thenational eradication campaigns reported the occurrenceof the last cases in their countries. These proceduresverified that smallpox transmission had in fact beenstopped.Benefit—cost AnalysisThe achievement of eradication means that smallpoxvaccination certificates for international travellers, androutine smallpox vaccination programmes, are no longernecessary. In fact, currently 78 countries have stoppedsmallpox vaccination programmes and the number isexpected to increase rapidly. All nations have abolishedthe requirement for an international certificate of small-pox vaccination from travellers, except in four instances—Chad, Democratic Kampuchea, Djibouti, and Mada-gascar—which still maintain the requirement.A total of US$313 millions (US$113 millions fromWHO and sources of international assistance, and roughlyUS$200 millions from the endemic-smallpox countriesthemselves) was spent during the last 13 years of thecampaign. The savings resulting from the termination ofthe vaccination programmes are estimated to be US$ 1000millions per year. Thus an equivalent of three months'expenditure should have ensured the elimination of thisdread scourge of humanity for all time!Post-eradication policyTo maintain the permanent status of eradication, apost-eradication policy has been established and is beingimplemented. Two hundred million doses of vaccine willbe reserved in case of an unexpected emergency.* Epi-demiological surveillance of suspected cases of smallpox,and research activities on poxviruses (the group to whichthe smallpox virus belongs), are continuing. The small-pox virus is now confined in test tubes in only six labo-ratories under strict security and constant surveillance.Isao Arita, ChiefSmallpox Eradication UnitWorld Health OrganizationAvenue Appia1211 Geneva 27Switzerland.REFERENCESHUQ, Farida (1976). Effect of temperature and relative humidi-ty on variola virus in crusts. Bull. Wld tilth Org., 54(6), pp.710-2.MacCALLUM, F. O. & McDONALD, J. R. (1957). Survival ofvariola virus in raw cotton. Bull Wld Hlth Org., 16(2), pp.247-54.•Including the abhorrent conceivability of 'Deliberate release'as a biological weapon in warfare or 'by an individual or group asan act of sabotage or terrorism', though 'unless the public healthservices had completely broken down, the outbreak that fol-lowed could be readily contained and the virus then eliminated'(The Achievement of Global Eradication of Smallpox: FinalReport of the Global Commission for the Certification of Small-pox Eradication. World Health Organization, Geneva, Switzer-land, WHO/SE/79.152, 122 pp., illustr. (mimeogr.).—Ed.Major Conservation Research Centre for ChinaChina and the World Wildlife Fund (WWF) haveannounced plans for a multi-million dollar, jointly-financed major conservation research centre to be builtin the highlands of Sichuan (Szechwan) Province insouthwestern China. Located in one of the main breeding-grounds of the Giant Panda (Ailuropoda melanoleuca),in the 200,000-hectares Wolong Nature Reserve, thecentre will concentrate initially on research on theendangered Giant Panda and its life-support system,which faces a major potential threat within the nextdecade. At a later date, the centre will expand its re-search to other species of animals and plants.Plans for the centre, which represents a cooperationwith foreign specialists that in some ways is probablyhttps:/www.cambridge.org/core/terms. https://doi.org/10.1017/S0376892900007487Downloaded from https:/www.cambridge.org/core. University of Basel Library, on 11 Jul 2017 at 12:31:20, subject to the Cambridge Core terms of use, available at

Smallpox Eradication: Man's Success in Eliminating a Most Dangerous Disease

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