Sometimes qualified as biological objects, viruses lie at the frontier of the living world. They nevertheless have an extremely strong impact on living organisms, whether plants or animals. So what differentiates them from other microscopic creatures such as bacteria, protozoans or fungi?
“Viruses are absolute parasites; they have no choice but to enter a cell in order to replicate,” explains Yves Gaudin, CNRS research professor and leader of a team in the Virology Department at the Institute for Integrative Biology of the Cell (I2BC).1 “They are strictly dependent on the metabolism of this host.” Unable to synthesise their own proteins, viruses are forced to divert the internal machinery of cells to their own benefit.
Virologists study these parasites that can mutate and cross the barriers between species, focusing in particular on those that are the most dangerous at a given time, but they also have the difficult task of trying to anticipate future epidemics. So which strategies do they adopt?