Researchers in France have announced an ancient virus has been revived after thousands of years of lying dormant. The virus had been discovered frozen under deep layers of Siberian permafrost. When thawed, experts found it was not only an active virus, but also infectious.
Frozen in time
According to BBC News, scientists said the virus had "come back to life" after "at least" 30,000 years. It had been found buried at a depth of 100 feet (30 meters) in the frozen ground. Haaretz reported the study's authors, Jean-Michel Claverie and Chantal Abergel, learned Russian scientists had resurrected an ancient plant and they started thinking about viruses, and asked the scientists for a permafrost sample to analyze. Upon examination, the team they'd assembled did find a virus—and a live one at that.
The virus, called Pithovirus sibericum, belongs to a relatively new class of viruses, discovered just 10 years ago. Referred to as "giant viruses", this type of virus can actually be seen without a microscope. This particular virus was reported to be a whopping 1.5 micrometers in length; the biggest found to date.
"This is the first time we've seen a virus that's still infectious after this length of time," Professor Jean-Michel Claverie, of the National Centre of Scientific Research (CNRS) at the University of Aix-Marseille in France said.
Risks from the virus?
Experts say the ancient virus does not pose a threat to humans or animals as it cannot infect either of them. It does, however, attack amoebas. Researchers did not discount the fact if other viruses are laying dormant under frozen ground and are exposed, there could be potential risk factors. With the ground in this region consistently warming up and defrosting since the 1970s, some experts say the permafrost could retreat even further unleashing other viruses.
"We are addressing this issue by sequencing the DNA that is present in those layers," said co-author Dr. Chantal Abergel, "This would be the best way to work out what is dangerous in there."
Abergel also warned that viruses / diseases thought to be eradicated may not be fully gone, just removed "on the surface."
Other experts, not involved in the study, are not sure viruses being unleashed would necessarily pose huge risks for society. For instance, Curtis Suttle, a virologist at the University of British Columbia in Vancouver, Canada, told media (courtesy Haaretz) people inhale thousands of viruses daily and also ingest billions when swimming in the ocean.
Do viruses ever freeze to death?
What is of concern is whether or not other viruses may be actively "living" under layers of ice just waiting to be exposed. Experts do indicate they do not know if all viruses can once again "come alive" or if it is only with certain classes or types. What they do know is this particular giant virus did become active upon defrost.
The full study, titled "Thirty-thousand-year-old distant relative of giant icosahedral DNA viruses with a pandoravirus morphology", was published in Proceedings of the National Academy of Sciences (PNAS).