Validation of a binary ethylenimine (BEI) inactivation procedure for biosafety treatment of foot-and-mouth disease viruses (FMDV), vesicular stomatitis viruses (VSV), and swine vesicular disease virus (SVDV).

Binary ethylenimine (BEI) has been widely used as a virucide to inactivate viruses. For regulatory exclusion of a select agent, the United States Federal Select Agent Program (FSAP) requires an inactivation procedure that renders a select agent non-viable but allows the select agent to retain antigenic characteristics for future use must be validated, and the inactivated agent must be confirmed by a viability testing. In this curve-based validation study, we examined impacts of BEI concentration, treatment temperature, and time on our in-house inactivation procedures of Foot-and-Mouth Disease Virus (FMDV), Vesicular Stomatitis Virus (VSV), and Swine Vesicular Disease Virus (SVDV). The inactivation efficacy was confirmed by virus titration and 3 consecutive blind passages on the monolayers of susceptible cells. A linear correlation between the virus titer reduction and BEI concentration, treatment time, and temperature was established. The results confirmed our in-house BEI inactivation procedure of two doses of 1.5 mM BEI treatment at 37 °C, 1st dose for 24 h, then 2nd dose for 6 more hours for a total of 30 h BEI contact time, can ensure complete inactivation of FMDV, VSV, and SVDV.