PVR and infection: A detailed analysis of formalin inactivation of poliovirus showed a reduction in the ability of viral particles (IPV) to bind to human poliovirus receptor (CD155) as compared to live poliovirus on the surface of the host cell that native polio virus interacts with during infection.34 Formalin treatment can also prevent the conversion from the native 160S viral particle to the structurally modified 135S particle, which is an important step for poliovirus to undergo cell entry.34 Finally, the formalin treatment completely prevents the infectivity of the viral RNA.