After realizing the goal of polio-free, there shall be no circulation of indigenous wild poliovirus, but still requires a high coverage rate of oral polio vaccine ( OPV), OPV may induce virus associated paralytic poliomyelitis ( VAPP) in few vaccinees and their contacts. 实现无脊髓灰质炎(脊灰)目标后,已无本土脊灰野病毒的循环,但需维持口服脊灰疫苗(OPV)的高免疫覆盖率。