Editing Asymptomatic carrier (section)

===Poliomyelitis===
A small number of asymptomatic carriers of [[polio]] (referred to as ''chronic excretors'') continue to produce active virus for years (or even decades) after their initial exposure to the oral [[Sabin vaccine]].<ref>{{cite journal|title=Update on Vaccine-Derived Polioviruses – Worldwide, January 2014–March 2015|author1=Ousmane M. Diop |author2=Cara C. Burns |author3=Roland W. Sutter |author4=Steven G. Wassilak |author5=Olen M. Kew |journal=Morbidity and Mortality Weekly Report |volume=64 |issue=23 |pages=640–646 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6423a4.htm|pmid=26086635 |pmc=4584736 |year=2015 }}</ref> Carriers of the [[attenuated vaccine|attenuated]] virus unintentionally spread the attenuated virus, inoculating others, giving them [[contact immunity]]; however some adults with weak immune systems have [[polio vaccine#Vaccine-induced polio|contracted paralytic polio]] from contact with recently immunized children. Carriers of virulent strains spread polio, increasing the difficulty of [[poliomyelitis eradication]].<ref>{{cite web | url=https://www.cdc.gov/pinkbook/hcp/table-of-contents/chapter-18-poliomyelitis.html | title=Chapter 18: Poliomyelitis | date=17 August 2021 }}</ref>