Can a virus be revived?

PithovirusIn Carl Zimmer’s New York Times article describing the recovery of the giant virus Pithovirus sibericum from the Siberian permafrost, he used the words revive and resurrect. Can a virus be restored to life?

The headline of the article read ‘Out of Siberian ice, a virus revived‘. Within the body of the article, Zimmer wrote ‘From Siberian permafrost more than 30,000 years old, they have revived a virus that’s new to science’, and later considered the ‘risk of an outbreak of resurrected viruses’. Both words mean ‘restore to life’.

When most people say ‘virus’ they usually mean the very small virus particle that infects cells. Virus particles are not living: they are assemblies of protein, nucleic acid, and sometimes lipids that do nothing until they infect a cell. That is why they are called obligate intracellular parasites. In the case of Pithovirus, infectious virus particles were present in the frozen sample that were able to infect amoeba in the laboratory.

To say that a virus was revived or resurrected is wrong, although I understand that the idea of bringing anything back to life has a great deal of general appeal. The key fact in this story is that the infectivity of the virus particle was maintained for over 30,000 years in the Siberian permafrost. I realize that this does not make for compelling headlines, but mine would have been: ‘Infectious virus recovered from Siberian ice after 30,000 years’. I suspect that Zimmer might understand this, but as he’s told me before, sometimes it’s much easier (and requires fewer words) to write something for the non-scientist that is not quite right.

Even virologists confuse the living with the non-living. When Paul Bieniasz and his laboratory reported that they had reconstituted an infectious retrovirus from viral sequences in the human genome, they used the phrase ‘the resurrection of this extinct infectious agent’.

A virus particle is not alive, but a virus infected cell certainly is living. A virus can be viewed as an organism with two phases, a non-living virus particle, or virion; and an infected cell, which is alive.  This definition solves the problem of whether a virus is alive or not, a subject of much debate here and elsewhere. Even if we use this terminology, the use of resurrect and revive to describe viral infectivity is still wrong, because virus particles cannot be brought back to life – they are not alive to begin with.