Parvovirus B19 Is Inactivated by Pasteurization, a Dedicated Virus Inactivation Step in the Manufacturing Process of Plasma-Derived Products.

Abstract 3152

Poster Board III-89

Human parvovirus B19 (B19V), a small non-enveloped virus, is the causative agent of the childhood disease erythema infectiosum (fifth disease) but causes, especially when the disease occurs during adulthood, a number of clinical symptoms as arthralgia, arthritis, (transient) aplastic crisis, anaemia, and hydrops fetalis (during pregnancy). B19V is normally spread via the respiratory route, however, parenteral transmission can occur through blood or blood components and plasma-derived products. In order to demonstrate the safety of plasma-derived products regarding B19V, virus validation studies are performed, using usually animal parvoviruses as models for B19V which indicate that this virus is highly resistant to commonly used inactivation methods as heat. Employing a cell culture infectivity assay for B19V, established at CSL Behring's virology laboratory, a considerable higher sensitivity of B19V to pasteurization (heat treatment in aqueous solution at 60°C for 10 hours) could be demonstrated for B19V in contrast to the animal parvovirus CPV (canine parvovirus). B19V was not only very sensitive to heat in unstabilised product intermediates but also heat sensitive when studying intermediates of various plasma products containing high concentrations of the stabilizers sucrose and glycine. Although these protein stabilizers had also a stabilizing effect on B19V this virus was nevertheless considerably more sensitive to pasteurization than CPV. As shown below, pasteurization results in an effective inactivation of B19V in a wide range of plasma-derived products.

Based on these experimental data on inactivation of B19V by pasteurization and a plasma pool for fractionation not exceeding 10⁴ IU B19V DNA/ml, the virus safety of plasma-derived products regarding B19V can be assessed more correctly demonstrating an appropriate margin of safety.