Smallpox killed more people than any infectious disease in the history of mankind, but an aggressive vaccination program that began in 1967 has eradicated the disease in humans.
There is still, however, smallpox left. Samples exist in laboratories in Atlanta and Russia, and although the World Health Organization recommended that they be destroyed in June, both countries want to keep their samples.
A confirmed case has not been seen in more than 20 years and people are no longer vaccinated.
The world organization is meeting this month to discuss the issue.
An editorial in this morning's international medical journal, The Lancet, warns that should the virus get out as a result of an accident or an attack, the world is not prepared.
The vaccine is no longer manufactured and existing stocks are so low, the editorial claims that no country could protect itself in the event of a major outbreak.
The concern is that a terrorist group could have the virus and release it into the population and it would be weeks or months before we realize why people were getting sick. Since it's a virus, there is no effective treatment except vaccination ahead of time.