Quote:‘Zombie’ virus revived after 50,000 years trapped in Siberian permafrost (November 25, 2022)

Researchers from the French National Centre for Scientific Research have revived more than a dozen prehistoric viruses that were previously trapped deep within the Siberian permafrost, according to a pre-print study.

From seven ancient permafrost samples, scientists were able to document 13 never-before-seen viruses that have been lying dormant, frozen in ice, over tens of thousands of years.

In 2014, the same researchers unearthed a 30,000-year-old virus trapped in permafrost, the BBC reported. 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.

Quote:Abstract

One quarter of the Northern hemisphere is underlain by permanently frozen ground, referred to as permafrost. Due to climate warming, irreversibly thawing permafrost is releasing organic matter frozen for up to a million years, most of which decomposes into carbon dioxide and methane, further enhancing the greenhouse effect. Part of this organic matter also consists of revived cellular microbes (prokaryotes, unicellular eukaryotes) as well as viruses that remained dormant since prehistorical times. While the literature abounds on descriptions of the rich and diverse prokaryotic microbiomes found in permafrost, no additional report about “live” viruses have been published since the two original studies describing pithovirus (in 2014) and mollivirus (in 2015). This wrongly suggests that such occurrences are rare and that “zombie viruses” are not a public health threat. To restore an appreciation closer to reality, we report the preliminary characterizations of 13 new viruses isolated from 7 different ancient Siberian permafrost samples, 1 from the Lena river and 1 from Kamchatka cryosol. As expected from the host specificity imposed by our protocol, these viruses belong to 5 different clades infecting Acanthamoeba spp. but not previously revived from permafrost: pandoravirus, cedratvirus, megavirus, and pacmanvirus, in addition to a new pithovirus strain.
.....
The biohazard associated with reviving prehistorical amoeba-infecting viruses is thus totally negligible, compared to the search for “paleoviruses” directly from permafrost-preserved remains of mammoths, woolly rhinoceros, or prehistoric horses, as it is now pursued in the Vector laboratory (Novosibirsk, Russia) [75], fortunately a BSL4 facility. Without the need of embarking on such a risky project, we believe our results with Acanthamoeba-infecting viruses can be extrapolated to many other DNA viruses capable of infecting humans or animals. It is thus likely that ancient permafrost (eventually much older than 50,000 years, our limit solely dictated by the validity range of radiocarbon dating) will release these unknown viruses upon thawing. How long these viruses could remain infectious once exposed to outdoor conditions (UV light, oxygen, heat), and how likely they will be to encounter and infect a suitable host in the interval, is yet impossible to estimate. But the risk is bound to increase in the context of global warming when permafrost thawing will keep accelerating, and more people will be populating the Arctic in the wake of industrial ventures.

An update on eukaryotic viruses revived from ancient permafrost

Quote:Can deadly virus and microbes survive in the ice?

An outbreak of anthrax in Siberia in 2016 caused the death of a 12-year-old-boy, hospitalization of scores of other people and the death of more than two thousand reindeer. The outbreak was traced back to an old reindeer corpse, which had melted out of the permafrost during what was the warmest Arctic summer on record.

The anthrax in Siberia outbreak generated a fear that other and perhaps even more dangerous microbes could be released from the melting ice, such as smallpox. Is it possible that malignant viruses and microbes, after hibernating in the ice for millennia, could be released by the on-going melt and pose a risk to humans?