Assessing country compliance with circulating vaccine-derived poliovirus type 2 outbreak response standard operating procedures: April 2016 to December 2020

Safety of the novel oral poliovirus vaccine type 2 (nOPV2) in infants and young children aged 1 to <5 years and lot-to-lot consistency of the immune response to nOPV2 in infants in The Gambia: a phase 3, double-blind, randomised controlled trial

“… 24 , 25 An absence of previous inactivated poliovirus vaccine immunisation in a proportion of participants in Liberia, technical issues related to the Liberia campaign or study, and inaccurate coverage data based on parental recall, are alternative explanations. 26 Such issues were avoided in the context of this rigorously controlled phase 3 trial but should be accounted for in public health policy decisions.…”

Infezioni in Medicina

“…A study from 2016 to 2020, there were 65 outbreak responses to cVDPV. Of the first large-scale campaign conducted after Day 0, only 12 (18.5%) such responses were conducted by the target date of 28 days after Day 0 of the occurrence of the outbreaks [63]. It was well stated that "without global eradication, there is a risk of re-infection from the importation and spread of wild poliovirus or VDPV, or the emergence and circulation of VDPV" [64].…”