If smallpox gets out...

摘要

An epidemic of smallpox could sweep rapidly through the modern world if the virus ever got out, a British study warns. Although smallpox is not as infectious as diseases such as chickenpox or measles, there could be "significant" epidemics. In the past, the spread of smallpox was held back by vaccination and people's natural immunity. But since the disease was eradicated in 1979, vaccination has ceased and levels of immunity have dropped dramatically. While all remaining stocks of smallpox are supposed to be locked up safely in two labs in the US and Russia, the anthrax attacks in the US have fuelled fears that terrorists might get hold of the virus.