Beacon Transcript – A centuries old child mummy may change smallpox virus history as it offers proof that the disease may have appeared later than initially believed.
Nowadays, smallpox has come to join the list of eradicated infectious disease. The eradication was declared official in 1979 by WHO or the World Health Organization. It was made possible by the vaccination campaigns carried out through the XIX and XXth centuries.
However, the smallpox virus caused havoc throughout history. As its two most common subtypes spread, the disease came to be called “the red plague”.
Previous theories considered that the smallpox virus first emerged around 10,000 BC. As yet, the oldest physical evidence of smallpox was found on the body of Ramses V.
A new study has come to nonetheless contradict this theory. Research made by a team of McMaster University scientists show that the virus may be younger.
The research was published earlier this week, on December 08, in the Current Biology journal. It was titled as follows. ”17the Century Variola Virus Reveals the Recent History of Smallpox”.
Henrik Poinar, the study’s lead author and McMaster University Ancient DNA Centre director released a statement.
In it, he pointed out the fact that science still has a lot to discover about smallpox. As Poinar points out, researchers do not yet understand the disease’s origin. They also do not know how it came to affect humans.
Poinar considers that the current research points out some interesting facts. It comes to contest the currently withheld smallpox age and perception.
Their new study suggests that the smallpox virus may not be as old as it is believed. Instead of being some thousands of years old, it may be closer than unexpected to us.
Research for the study was based on DNA samples extracted from a mummy. The mummy holds the body of a child believed to have died sometimes in between 1643 to 1665.
During that period, smallpox was a quite common occurrence throughout Europe. As such, the Lithuanian partially mummified remains contained the needed virus DNA samples.
The extracted smallpox virus DNA was heavily fragmented but yielded the necessary strain sequences.
After comparing the 17th to the available 20th-century smallpox virus strains, researchers reached the following conclusion.
They determined that both virus samples and subsequent strains originate from a 1580’s ancestor.
Edward Holmes, study co-author and a University of Sydney evolutionary biologist offered further explanations.
According to Holmes, their study places the smallpox virus evolution chain much closer to us. The actual initial carrier of the disease has yet to be determined.
Holmes states that most believe that such a first virus bearer must have been an animal. Also, the time period around which the virus jumped into humans is also to be determined.
Whilst carrying out their study, the researchers unearthed another interesting find. It would appear that the deadly virus pathogen began breaking into a minor and major strain after 1796.
Interestingly enough, 1796 is the appearance year of the first smallpox vaccine. It was developed by an English scientist and physician, Edward Jenner.
According to Ana Duggan, this fact raises relevant questions about a pathogen’s evolution. Dugan is a McMaster Ancient DNA Centre postdoctoral fellow and study co-author.
She states that this find could help establish a pathogen’s diversification methods when faced with a vaccine.
Although the virus has stopped occurring naturally in humans, Dugan also draws a warning. She considers that humans should not rest until the smallpox virus origins are discovered.
According to her, only by knowing its origin can we stop a potential reemergence.
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