Emerging Viruses Are Inactivated by Pasteurization.

Emerging zoonotic viruses as West Nile virus (WNV), SARS coronavirus, and avian influenza viruses have raised concern about their potential presence in blood/plasma. However, so far only WNV has been demonstrated to be transmitted via blood transfusion. Pasteurization (heat treatment in aqueous stabilized solution at 60°C for 10 hours) is an integral part of the manufacturing process of ZLB Behring's coagulation factor concentrates such as Haemate P / Humate-P, Monoclate-P, Beriate P, and Berinin P as well as other plasma-derived medicinal products. Therefore, the virus inactivation capacity of this manufacturing step was evaluated utilizing these emerging viruses or appropriate model viruses in virus spiking studies in order to assess the safety of plasma derivatives. The studies demonstrated that WNV was inactivated very effectively by pasteurization in different plasma derivatives resulting in an inactivation factor of more than 7 log(10) and that BVDV (bovine viral diarrhea virus, as WNV a member of the family Flaviviridae) is a suitable model virus for WNV. Furthermore, coronaviruses and influenza viruses, of both avian and human origin, were highly susceptible to inactivation by pasteurization resulting in complete inactivation of virus infectivity within a short period of time. In addition, feline calicivirus, a model virus for hepatitis E virus (HEV), was inactivated very effectively within a short period of time. We demonstrate that pasteurization is an effective method to inactivate the emerging viruses WNV, SARS coronavirus, and avian influenza viruses as well as HEV below detection limit of a sensitive cell culture infectivity assay resulting in a safe plasma derivative.