Effective inactivation of a wide range of viruses by pasteurization

Gröner, Albrecht; Broumis, Connie; Fang, Randel; Nowak, Thomas; Popp, Birgit; Schäfer, Wolfram; Roth, Nathan J.

Herpesviruses, employed as nonspecific model viruses, were inactivated effectively by pasteurization. Different herpesviruses, belonging to different herpesvirus genera or species, showed varying inactivation kinetics by pasteurization. The human herpesvirus HSV was rapidly and completely inactivated with RFs of approximately 6 log or more, whereas the porcine herpesvirus PRV (genus Varicellovirus) generally showed partial heat resistance in process intermediates stabilized with sucrose, with virus RFs generally in the order of 4 log. Limited data sets are available for HHV-5 (genus Cytomegalovirus), the BoHV-1 (genus Varicellovirus), and EHV-1 (genus Varicellovirus), pasteurized in a standard stabilizer (sucrose, glycine, and/ or potassium acetate, Table 1 ). A rapid inactivation kinetic was demonstrated for HSV, HHV-5, and EHV-1 whereas PRV and BoHV-1 (belonging to the same genus as PRV) were inactivated at a slower rate (Fig. 2) . In contrast to other herpesviruses studied and to all other enveloped viruses studied, the inactivation kinetic of PRV was dependent on the sucrose concentration (Fig. 3) . Interestingly, addition of PRV to the stabilized, nonheated product intermediates resulted in a rapid reduction of virus titer by approximately 1.5 log (data not shown). In an in vivo infectivity study using ducklings, DHBV was inactivated below LOD of the duck infectivity assay after 2 hours pasteurization resulting in a virus RF of at least 6.5 log. 6 Emerging viruses or respective model viruses were studied in stabilized VWF/FVIII: the flaviviruses WNV, YFV, the influenza viruses H1N1 and H5N1, the bunyavirus LACV, and the coronaviruses SARS-CoV and TGEV. Effective inactivation of these viruses was demonstrated with no residual infectivity detected by 6 hours (Fig. 4) .