Seven viruses have been revived from Siberian permafrost and multiplied in the laboratory. Among them is the oldest virus “resurrected” to date.
Seven species of viruses that were frozen for thousands of years in Siberian permafrost have been brought back to life. The youngest of them have been frozen for 27,000 years, while the largest have been frozen in ice for 48,500 years. This makes the latter the oldest virus ever revived.
“48,500 years is a world record,” says microbiologist Jean-Michel Clavery of Aix-Marseille University in France, who conducted the work with colleagues. His team previously revived two 30,000-year-old permafrost viruses. The first virus was announced in 2014.
Alzheimer’s drug research has been wrong for a long time
The fact that all nine viruses remained able to infect cells shows that ancient viruses from thawing permafrost pose a threat to the health of plants and animals, including ourselves.
250 million years
While 48,500 years may be a record for a virus, several groups claim that it has resurrected bacteria that have been trapped in sediment, ice, or salt crystals for up to 250 million years. However, it remains unclear whether the organisms are actually ancient. It could be younger organisms that contaminate the samples.
He says the nine viruses revived by Claverie’s team are unlike any previously known. It is therefore unlikely that they were caused by contamination of the sample with recent variants. The team discarded several other viruses that had allegedly been revived because their genomes were too similar to those of known viruses.
According to Clavery, it is entirely possible to revive much older viruses. The deepest permafrost reaches a million years. However, it is difficult to determine the age of ancient permafrost because standard radiocarbon dating does not work for samples older than 50,000 years.
The 48,500-year-old virus emerged from permafrost 16 meters below the bottom of a lake in the Yukichi Alas in Yakutia, Russia. It’s the Pandora virus. A giant virus that infects single-celled organisms known as amoebas. All nine viruses the team has recovered so far are giant viruses that infect amoeba, because that’s the only thing the team is looking for.
The researchers added permafrost samples to the amoebic cultures. Then they examine it under a microscope for signs of infection. This indicates that the virus is “alive” and multiplying.
If ancient giant viruses remained infectious after such a long freeze, Clavery said, so would other species. Eric Delwart, a molecular virologist at the University of California, San Francisco, who has recreated plant viruses from old frozen reindeer droppings, agrees. “If the authors did indeed isolate live viruses from ancient permafrost, it is likely that smaller, simpler mammalian viruses could also survive frozen for very long periods of time.”
This means there is a risk that these ancient viruses could infect plants or animals, including humans, if thawed, Claverie says. According to him, this risk is increasing due to the melting of permafrost due to climate change. “Bacteria and viruses come out of it every day.”
Clavery says that while few people in the Arctic are exposed to such threats of infection, more and more people are moving there to extract resources like gold and diamonds. The first step in mining is to remove the top layers of permafrost. “There is a real danger,” he says. “But it is impossible to quantify these risks.”
Delwart believes the risk of an ancient virus in permafrost causing a pandemic is much lower than the risk of viruses circulating in domestic and wild animals. “Global warming is terrifying enough without adding the release of deadly frozen viruses to the long list of projected environmental disasters,” he says.
But Rebecca Katz, an epidemiologist at Georgetown University in Washington, D.C., says we must take this risk seriously. “It makes sense to understand all the possible ways these viruses emerge so that we can be as prepared as possible,” she says. “The threat of ancient viruses emerging from the thawing permafrost is very real.”
Deliberate attempts to revive permafrost viruses could also be risky, Clavery says. He adds that his approach is safe because viruses that infect amoeba cannot infect plants or animals. However, a team from Russia’s State Research Center for Virology and Biotechnology plans to revive viruses that infect mammoths, Claverie says. ‘This terrible. I am totally against that.