Scientists from the French National Centre for Scientific Research revived 13 never-before-seen viruses from seven ancient permafrost samples. The oldest virus has been named Pandoravirus yedoma, which was discovered in a sample taken from the bottom of Yukechi Alas lake in Russia. It is 48,500 years old.
In 2014, the same researchers had unearthed a 30,000-year-old virus trapped in permafrost. The discovery was groundbreaking because after all that time, the virus was still able to infect organisms. But now, they’ve beaten their own record by reviving a virus that is 48,500 years old.
Scientists are thawing out these ancient viruses in order to assess their impact on public health.
According to a scientific study, which is yet to be peer-reviewed, global warming is irrevocably thawing enormous swathes of permafrost — permanently frozen ground that covers one-quarter of the Northern Hemisphere.
This has had the unsettling effect of “releasing organic materials frozen for up to a million years” – possibly deadly viruses included.
“The situation would be much more disastrous in the case of plant, animal, or human diseases caused by the revival of an ancient unknown virus,” reads the study.
Are the viruses dangerous to humans?
Some of these “zombie viruses” could potentially be dangerous to humans, the authors warn. And, in fact, thawing permafrost has already claimed human lives.
In 2016, one child died and dozens of people were hospitalized after an anthrax outbreak in Siberia. Officials believe the outbreak started because a heat wave thawed the permafrost and unearthed a reindeer carcass infected with anthrax decades ago. About 2,300 reindeer died in the outbreak.
The latest revived viruses that researchers spotted belong to the following sub-types of viruses: pandoravirus, cedratvirus, megavirus, pacmanvirus and pithovirus. These viruses are considered “giant” because they’re large and easy to spot using light microscopy.
For this reason, researchers believe there are many other smaller viruses that have escaped scrutiny.
One silver lining is that the study’s authors say there is a “negligible” risk of these amoeba-infecting viruses having a hazardous impact on humans. But that’s not to say that all ancient viruses are harmless.
It’s unclear if these ancient viruses would be able to infect a host once exposed to outdoor conditions like heat, oxygen and UV rays. But researchers say the chance of such a situation is increasing as more of the permafrost thaws and more people begin to occupy the melting Arctic for commercial and industrial ventures.
They believe that Covid-19-style pandemics will become more common in the future as melting permafrost releases long-dormant viruses. “It is therefore legitimate to ponder the risk of ancient viral particles remaining infectious and getting back into circulation by the thawing of ancient permafrost layers,” said the study.
(With inputs from agencies)