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Global Update

Indian Pediatrics 2002; 39:317-318  

Smallpox - A Potential Biowarfare Weapon: Destroy the Virus or Keep the Vaccine for Ever


While the last case of smallpox in India, an importation from Bangladesh, occurred in Assam on 24 May 1975(1), the last known naturally transmitted case of smallpox in the world occurred in Somalia on 26 October 1977(2) and it was thought that this deadly human scourge is finally over. However, within a year the laboratory associated cases of smallpox occurred in Birmingham, UK(3). The global eradication of smallpox was certified by a commission of eminent scientists in December 1979 and subsequently endorsed by the World Health Assembly (WHA) in May 1980(4). Consequently, WHO recommended that all countries stop smallpox vaccination programmes and that only individuals at risk of exposure (for example, laboratory researchers working on smallpox or monkeypox) should be vaccinated with smallpox vaccine(5).

Many laboratories stored smallpox virus before the disease was eradicated. Now only 2 laboratories hold the virus officially. These are State Research Center of Virology and Biotechnology (VECTOR), Koltsovo, Novosibirsk Region, Russia, and the Centers for Disease Control and Prevention (CDC), Atlanta, Georgia, USA(6). The others were asked in 1980s to either destroy it or transfer it to either of the two authorized laboratories(3). In 1996, the WHA agreed to the complete destruction of virus by June 1999(6). In May 1999, the WHA reaffirmed the decision to destroy the remaining stocks of variola virus, but authorised temporary retention of the stocks upto the end of 2002 to permit further international research(7). This however, is unlikely to happen. USA has now decided to retain the virus until scientists develop new vaccine (which can be taken by the entire population) and treatment for the disease and other defensive measures, a process that may take many years or even decades to complete(8).

Some governments believe that the variola virus has been retained in places other than the two authorized laboratories and that it may be deliberately released to cause harm(3). If it happens, it will prove disastrous in the affected areas and create panic in the whole world. All the countries which have retained the smallpox vaccine have only limited stock. In the event of an outbreak, they are unlikely to spare the vaccine for other countries.

A WHO survey conducted in 1998 indicated that approximately 90 million declared doses of smallpox vaccine were available world-wide(9). USA has small- pox vaccine that is believed to be sufficient to vaccinate between 6 and 7 million persons(10). WHO collaborating center for Smallpox Vaccine in Bilthoven, the Nether-lands, is holding about 500,000 doses of vaccine on behalf of the WHO (Arthur RR, WHO: Personal Communication). This center is also holding the seed virus (vaccinia virus strain Lister Elstree) used to produce the vaccine(9). India stopped the vaccine production in 1979.

Individual countries that have reason to believe that their people face an increased risk of smallpox because of deliberate use of the virus are considering options for increasing their access to smallpox vaccines(11). Increasing attention is being given to the extent and quality of existing vaccine stocks, and to the possible need both to stimulate vaccine production and increase stocks of vaccine for use in the event of an outbreak(11).

Keeping in view the above, it is unlikely that we can assure ourselves that the globe will be free from smallpox virus in the near future. Therefore, what we need is to maintain our capability to intercept early epidemiological clues through continuing medical education, demonstrate capability in laboratory expertise using molecular techniques, have immediate access to the vaccine and maintain production capability to meet any eventuality.

K.K. Datta,
Jagvir Singh,

National Institute of Communicable Diseases, 22 Shamnath Marg,
Delhi 110 054, India.

E-mail:
[email protected]

 References


1. Basu RN, Jezek Z, Ward NA. The Eradication of Smallpox from India. World Health Organization Regional Publication, South-East Asia Series No.5, WHO, India, South-East Asia Regional Office, New Delhi, 1970.

2. World Health Organization. The Global eradication of smallpox. Final Report of the Global Commission for the Certification of Smallpox Eradication. World Health Organization, Geneva, 1980.

3. World Health Organization. Frequently asked questions and answers on Smallpox, 26 October 2001.

4. World Health Organization. WHO fact sheet on smallpox. http://www.who.int/emc/disea ses/smallpox/factsheet.html.

5. World Health Organization. Note for the Press No. 15, 19 October 2001.

6. World Health Organization. Press Release WHA/11, 21 May 1999.

7. World Health Organization. Smallpox eradication. WHO Advisory Committee on Variola Virus research. Wkly Epidm Rec 2000; 75: 45-52.

8. Miller J. US set to retain smallpox stocks. The New York Times, 16 November 2001.

9. World Health Organization. Smallpox. Wkly Epidm Rec 2001; 76: 337-344.

10. Henderson DA, Inglesby TV, Bartlett JG, Ascher MS, Eitzen E, Jahrling PB, et al. Smallpox as a biological weapon. JAMA 1999; 281: 2127-2137.

11. World Health Organization. Statement WHO/16-26 October 2001.

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