Smallpox is one of the deadliest viruses in human history- but how was it eradicated?
10 July 2014
Presented by Ginny Smith, Hannah Critchlow


Smallpox vaccine poster


US government this week discovered vials of smallpox virus whilst cleaning out an old storeroom. This was shocking, as it was thought that the only 2 remaining samples were securely stored in Atlanta and Russia. It is not yet known if the samples found were alive, and so if they posed any health threat.

In this episode

Smallpox vaccine poster

00:00 - Smallpox

US government this week discovered vials of smallpox virus whilst cleaning out an old storeroom.


·         Smallpox is caused by the variola virus, and is spread by direct contact with Smallpox vaccine posterinfected bodily fluids.

·         The symptoms include fever, aches and the spots or 'pox' that give the illness its name.

·         In the past, the disease killed a third of all infected adults, and up to 80% of children. By the end of the eighteenth century, in Europe, this meant the death of 400,000 people each year, including five kings. Many more were left blind.

·         While there is no known treatment, vaccines can provide lasting immunity. But using the live smallpox virus as a vaccine was dangerous, as people could become ill and die.

·         In 1796, a doctor called Edward Jenner discovered that giving people a dose of cowpox left them with immunity to smallpox.  This made the vaccination process much less dangerous, as cowpox was a much milder illness.

·         Vaccination was so successful that the number of cases dropped dramatically, and by the 1970s, vaccination was no longer necessary.

·         The last known natural case of smallpox was in 1977, but in 1978, a photographer working in a lab became accidentally infected and died,

·          In 1979 WHO certified that smallpox had been eradicated, and began a global effort to keep track of the remaining stocks of the virus. By 1983, all known stocks had been destroyed, or brought to one of 2 holding centres- in Atlanta and Russia.

·         In 1990, the WHO recommended that these last two known stocks should be destroyed, to prevent accidental release.

·         Some scientists, however, argued that they should be kept. They believe we need to understand more about the viruses in order to protect ourselves from possible bioterrorism.

·         Another fear is that the virus could re-emerge naturally, perhaps from melting perma-frost. If we no longer had the sample, we would be unable to create new antiviral drugs.

·         At the moment, two advisory groups to the WHO disagree about whether the remaining virus should be destroyed, so the decision has again been delayed while a third advisory group is set up to discuss the matter. 


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