Modulation of the host immune response by cowpox virus.

Cowpox virus, a zoonotic poxvirus endemic to Eurasia, infects a large number of host species which makes its eradication impossible. The elimination of world-wide smallpox vaccination programs renders the human population increasingly susceptible to infection by orthopoxviruses resulting in a growing number of zoonotic infections including CPXV transmitted from domestic animals to humans. The ability of CPXV to infect a wide range of mammalian host is likely due to the fact that, among the orthopoxviruses, CPXV encodes the most complete set of open reading frames expected to encode immunomodulatory proteins. This renders CPXV particularly interesting for studying poxviral strategies to evade and counteract the host immune responses.