Co-operative thermal inactivation of herpes simplex virus and influenza virus by arginine and NaCl

Elevated temperatures have been used to inactivate viruses for plasma-derived biopharmaceuticals. This paper describes the effects of arginine and NaCl in conjunction with elevated temperature for inactivation of two enveloped viruses, i.e., herpes simplex virus type 1 (HSV-1) and influenza virus type A at neutral pH. In phosphate-buffered saline, a significant inactivation of HSV-1 occurred above 40 °C, resulting in less than 10% surviving virus (over 90% virus inactivation) at 50 °C. Arginine concentration dependently decreased the temperature required for virus inactivation, leading to temperature shift by almost 17 °C at 1.2 M. NaCl also decreased the inactivation temperature, but to a considerably lesser extent, indicating that virus inactivation effect of arginine is not simply due to ionic strength. Influenza virus was also inactivated by high temperature, but its responses to arginine and NaCl were different from those on HSV-1, suggesting that virus inactivation mechanism is different between these two viruses, i.e., the effects of these reagents are virus specific.