[Genetic variation and recombination have profound medical implications].

In the family Herpesviridae, the subfamily Alphaherpesvirinae contains numerous pathogenic viruses, i.e. herpes simplex and varicella-zoster viruses. These double-stranded DNA viruses exhibit a complex cycle combining lytic and latent infections. Moreover, both intranuclear replication and a sophisticated DNA replication machinery allow an efficient proof-reading mechanism of correction. A low mutation rate is therefore encountered by these viruses. Recombination can be identified as a key element of the genetic biodiversity of alphaherpesviruses, together with mutations. The experimental data recently obtained in the bovine herpesvirus 1 homologous model support the importance of recombination in alphaherpesvirus evolution and its role in the mechanisms involved by the virus to escape from medical tools of prevention and treatment.