Polio can range in severity from an apparent infection without any symptoms or meningitis, to paralytic disease and even death due to paralysis of the muscles or respiration.

• 小儿麻痹症可能会由没有任何症状与脑膜炎发作的显性感染病情突然加剧，导致麻痹瘫痪，甚至由于肌肉和呼吸系统衰竭而死亡。