**in recent 12 months no local transmission in Southeast Asia
*cVDPV3 is not identified so far
*VDPV is relatively physically stable in environment but cannot keep infectivity not for long time, thus continuous detection of VDPV in enviromnent means continuous transmission and/or excretion of VDPV from people living in the community
*distribution of breech (disinfectant) and/or irradication ultraviolet light may be effective against PV/VDPV
*threshold of immunization coverage to maintain PV/VDPV free is 85-90%
==Global Polio Eradication
**⇔Variola cases and true smallpox infection overlapped almost identically