Inactivation of hepatitis A variants during heat treatment (pasteurization) of human serum albumin

BACKGROUND: Pasteurization of human serum albumin (HSA) is detailed in the US and European Pharmacopoeial monographs and therefore a process that allows for little variation in physiochemical variables. Nevertheless, differences of up to 3.9 log in hepatitis A virus (HAV) inactivation by pasteurization have been reported. Here, the hypothesis that the choice of HAV variant used in the pasteurization might contribute to this inactivation variability is evaluated experimentally. STUDY DESIGN AND METHODS: The identity of four widely used cytopathic variants of the original HAV HM175 strain was determined by partial sequencing. These variants were used in pasteurization studies conducted under the principles of good laboratory practice, for which HAV-spiked HSA of 5 or 25% protein content was kept at 58 1°C for 600 10 minutes, and the