Giant, prehistoric virus thawed from Siberian permafrost.

New Scientist is not (we hope) introducing a 1950s-style horror film with their story on the giant, prehistoric virus THAT LIVES AGAIN:

Dubbed a pithovirus after the Greek pithos, meaning a large earthenware jar like an amphora, the virus infects amoebas but does not appear to harm human or mouse cells.

Even so, now that this virus has been revived from the permafrost, so too could potentially harmful pathogens, possibly including viruses humans have never encountered before, the researchers say.

“There’s good reason to think there could be pathogenic viruses in there too,” says Chantal Abergel of Aix-Marseille University in Marseille, France, and co-leader of the team that discovered the virus.

The pithovirus itself is very different from any known virus. At 1.5 micrometres long by 0.5 micrometres wide, it is around 30 per cent bigger than what had been the largest known virus – the pandoravirus, also found by Claverie’s team.

Yet despite being physically larger, the pithovirus has only a fifth as many genes as the 2500 in the pandoravirus. The two giant viruses share just five genes.

Reviving the pithovirus needed no sophisticated techniques. Rather, Claverie and Abergel “baited” the peat-like permafrost sample with amoebas. “We used the amoebas to draw out the virus, as we know these giant viruses tend to infect amoebas,” says Claverie.