With what seems to be from a plot of a bad science fiction movie, scientists have brought back a virus in the laboratory that had been lying dormant in ice for 30,000 years, from the time of saber-toothed tigers and wooly mammoths. And not just any virus, but the Pithovirus sibericum, the largest that has ever been found measuring 1.5 micrometres in length. It belongs to a class of relatively huge viruses that was first discovered just 10 years ago, and is big enough to be seen under a microscope.
No need to worry, though, as the virus does not infect humans or animals, rather it just attacks amoebas, which are single-celled organisms. Dr. Chantal Abergel, from the National Centre of Scientific Research in France (CNRS), explained that “it comes into the cell, multiplies and finally kills the cell. It is able to kill the amoeba- but it won’t infect a human cell.”
Research suggests, however, that as more ice that has been frozen since the last ice age starts to melt, more ancient viruses that could potentially be harmful to humans might be unearthed. Jean-Michel Claverie, also from the CNRS, said, “This is an indication that viruses pathogenic for human or animals might also be preserved in old permafrost layers, including some that have caused planet-wide epidemics in the past.”
Particularly an old strain of the smallpox virus, which was declared eradicated 30 years ago but, according to Claverie, was eradicated on “only the surface.” He goes on to say that “by going deeper we may reactivate the possibility that smallpox could become again a disease of humans in modern times.”
The region in Siberia that the Pithovirus sibericum was found in is being looked at for its natural resources, which worries those that discovered the amoeba-killing virus, particularly Claverie. “It is a recipe for disaster. If you start having industrial explorations, people will start to move around the deep permafrost layers. Through mining and drilling, those old layers will be penetrated and this is where the danger is coming from.”
It is not clear, however, if other viruses could become active again after being in ice for thousands of years. “This is the first time we’ve seen a virus that’s still infectious after this length of time,” said Claverie. The odds might be slim, as “it’s the freezing-thawing that poses the problems, because as the ice forms then melts there’s a physical damaging effect. If they do survive this, then they need to find a host to infect and they need to find them pretty fast.”
Even if they do find hosts to infect and the viruses start to circulate, the idea that those viruses are potentially more harmful to mankind than the thousands that people inhale and swallow every day going about normally “stretches scientific rationality to the breaking point,” according to Curtis Suttle, a virologist at the University of British Columbia.
So don’t worry too much. Ancient viruses that get resurrected might not really affect humankind’s survival significantly. We can hope.