In vitro and in vivo potency tests for inactivated poliovirus vaccine (IPV) have no experimental model by which they may be correlated with protection against disease caused by poliovirus. Studies conducted at LMD have demonstrated and characterized the protective effect of vaccination with IPV against lethal poliovirus challenge in transgenic (Tg) mice carrying the human poliovirus receptor (PVR). Application of the protection model has so far shown differences in protective effect for different IPV antigens and virus strains used for manufacture of IPV. The relationship between IPV dose, vaccination regimen, and protective response are similar for poliovirus types 1 and 3.