• Poliovirus, picornaviridae

  • Vaccine-derived poliovirus (VDPV): The live attenuated poliovirus strains in OPV can circulate in a community for an extended period of time and cause cases of paralytic poliomyelitis, known as circulating vaccine-derived poliovirus (cVDPV), and accumulate further mutations.

Epidemiology & transmission

  • Oral transmission, humans are the only natural hosts and reservoir


  • Selectively infects and destroys anterior horn cells in the spinal cord, resulting in 'acute flaccid paralysis' (although 99% of infected people show no paralytic manifestations)

  • Wild poliovirus cans have decreased by >99% since 1988 (350,000 cases to 22 in 2017)

  • Endemic transmission in Afganistan, Nigeria, Pakistan


Oral polio vaccine () SALK

  • vaccine-associated : vaccinated individual and close contacts

  • vaccine-derived poliovirus (VDPV)

  • bivalent and multivalent OPV (bOPV, mOPV2, and ... tOPV again)

Inactivated poliovirus vaccine (IPV)

  • low- and middle-risk countries. Qualified for routine immunisation. Global introduction of IPV from 2016 (at least one dose). Multivalent inactivated vaccines available SABIN


Basic strategies of polio eradication

  • Extensive immunisation with OPV (IPV)

  • Acute flaccid paralysis (AFP) surveillance

  • Lab diagnosis


Vaccine associated....


Stop Polio

Global WPV1 & cVDPV cases (Oct 2019-Oct 2020)

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