[Incidents in reposition of smallpox virus laboratories and its retrospect and ponderation].

Reposition of variola virus in some laboratories in the UK led to some serious incidents before the announcement by WHO of the Global Eradication of Smallpox in 1980. These three incidents resulted in 78 people recorded as infected with smallpox, among them 3 died, with very many others misdiagnosed at the time as suffering from chickenpox. Therefore WHO discussed the problems and decided to reduce gradually the number of repositories of variola virus in laboratories world-wide from previously unknown numbers to two. However, suppose in the event of a sudden outbreak of a new, mutated species of smallpox virus, what should we do? Maybe, the obsolete ancient prophylactic practice of variolation could be of considerable contingency value.