In a study that has yet to be published, scientists from France’s National Centre for Scientific Research have successfully resurrected more than a dozen ancient viruses from the depths of the Siberian permafrost. Thirteen previously unknown viruses were discovered in seven permafrost samples that had been frozen for at least tens of thousands of years.
According to the BBC, in 2014 the same team of researchers discovered a virus that had been frozen for the previous thirty thousand years. The fact that the virus was able to infect organisms after all this time was a major breakthrough in the field. They had previously revived a virus that was 48,500 years old, but now they have set a new record. The large, ancient virus is known as Pandoravirus yedoma, a name that reflects the particular kind of permafrost soil in which it was first discovered.
To better understand the dangers they pose to modern society, scientists are reviving long-frozen viruses from the past. In the Northern Hemisphere, where the ground is perpetually frozen, melting ice releases vast quantities of chemicals and microbes that had been frozen in. As a result of global warming, permafrost is defrosting and releasing organic matter that had been frozen for up to a million years; this material breaks down primarily into carbon dioxide and methane, which contribute further to the greenhouse effect.
The authors warn that some of these zombie viruses may pose a threat to human health. Indeed, human lives have been lost due to the thawing of permafrost. In 2016, an anthrax eruption in Siberia claimed the life of a young child and sent dozens more to the hospital. There was an outbreak of anthrax, and officials believe it started when a heat wave thawed the permafrost and exposed a reindeer carcass contaminated with the disease decades earlier. A total of 2,300 reindeer were lost due to the disease.
Pandoraviruses, cedratviruses, megaviruses, pacmanviruses, and pithoviruses were identified among the resurrected viruses. The term “giant” is applied to these viruses because of their size and visibility under a light microscope. This leads scientists to speculate that there are lots of other, smaller viruses that have been overlooked so far.