Scientists have thawed 7 different types of virus from the Siberian permafrost, including the oldest to emerge from the ice so far: the virus in the group to have been preserved the shortest was 27,000 years old, while the age record was beaten by a microbe of 48,500 years . The group recovered 9 viruses in total, which were able to infect cells, which shows the danger posed by frozen microorganisms to the world’s fauna and flora.
There is nothing to fear about the study specimens, however: they are all giant viruses that infect amoebas, single-celled organisms analyzed under a microscope. The oldest specimen, for example, is a type of pandoravirus. Scientists specifically looked for this type of pathogen, avoiding potentially harmful ones.
Other researchers have already reported having managed to thaw older organisms, specifically bacteria trapped in sediments, salt crystals or ice from 250 million years ago: doubts are raised, however, about their real age, since they could be samples contaminated by more recent.
Weighing in favor of the record-breaking virus is the fact that all 9 specimens are unlike any known to science, so it is extremely unlikely that they were infected by newer viruses. The team even discarded many other resurrected samples because of their genomes, which were very similar to those we already know.
It is possible, according to experts, that the future will allow us to revive much older viruses, as the oldest permafrost is up to 1 million years old. There are difficulties for a more specific dating in this case, since the standard method, with radiocarbon, only allows us to reach accurately up to 50,000 years ago. The 48,500-year-old virus was 16 meters deep in a lake in Yukechi Alas, in the province of Yakutia, Russia.
The success of the thawing, shown by the successful replication of the viruses in the laboratory, raises fears that smaller entities, which would manage to infect mammals, would eventually break out of the ice unwittingly. Climate change, which has been melting the permafrost of glaciers around the world, releases new viruses and bacteria every day, according to science.
Is there danger to humans?
In the Arctic, where the team worked, there are few humans, but more and more workers are going to the region to mine gold and diamonds. The first stage of this process is precisely to break the upper layer of permafrost. The danger exists, say scientists, but it is not possible to quantify it. The risk of a pandemic is at least lower than that generated by viruses circulating in domesticated and wild animals.
There are still possible dangers posed by purposely thawed viruses: The team behind the current study, published in the scientific journal bioRxiv on November 10 of this year, avoided microbes that can infect humans, but there are other researchers trying, for example, to resurrect viruses that infected mammoths, which is considered extremely dangerous.