Deadly smallpox not eradicated, scientist warns By Steve Connor, Science Editor in Geneva 22 October 2003 The return of smallpox - one of the most lethal diseases in history - is a terrifying possibility, according to the scientist who ran the World Health Organisation's campaign to eradicate the virus in the 1970s. Donald Henderson, a senior science adviser to the US government, said past assurances from certain countries claiming to have destroyed their smallpox stocks could no longer be believed. At least 30 million people are thought to have died from the disease in the 20th century. WHO scientists declared...