Editing Polio (section)

===Circulating vaccine-derived polioviruses===
The [[oral polio vaccine]], while highly effective, has the disadvantage that it contains a live virus which has been [[Attenuated vaccine|attenuated]] so that it cannot cause severe illness. The vaccine virus is excreted in the stool, and in under-immunized communities it can spread from person to person. This is known as '''circulating vaccine-derived poliovirus''' (cVDPV) or more simply as '''variant poliovirus'''.<ref name="www.cdc.gov2022" /><ref>{{cite web |title=GPEI-Variant Poliovirus (cVDPV) |url=https://polioeradication.org/polio-today/polio-prevention/the-virus/variant-poliovirus-cvdpv/ |access-date=2024-08-07 |website=Global Polio Eradication Initiative |language=en-GB}}</ref>

With prolonged transmission of this kind, the weakened virus can mutate and revert to a form that causes illness and paralysis. Cases of cVDPV now exceed wild-type cases, making it desirable to discontinue the use of the oral polio vaccine as soon as safely possible and instead use other types of polio vaccines.<ref name="www.cdc.gov2022" /><ref>{{cite web |title=GPEI-Vaccine-Derived Polioviruses |url=https://polioeradication.org/polio-today/polio-prevention/the-virus/vaccine-derived-polio-viruses/ |access-date=2022-09-03 |archive-date=28 August 2022 |archive-url=https://web.archive.org/web/20220828160534/https://polioeradication.org/polio-today/polio-prevention/the-virus/vaccine-derived-polio-viruses/ |url-status=live }}</ref>