Poliomyelitis is an acute infection caused by polioviruses. Oral poliovirus vaccines are live attenuated viral vaccines and the vaccine virus in OPV can mutate and acquire neurovirulence causing paralysis either due to vaccine-associated paralytic polio (VAPP) or due to circulating vaccine-derived polioviruses (cVDPV), in which the attenuated vaccine virus not only acquires the ability to cause paralysis but can also circulate similar to wild poliovirus (WPV). Therefore, polio eradication will require eventual cessation of all OPVs.