Imperial College London


Faculty of MedicineSchool of Public Health




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BibTex format

author = {Blake, IM and Pons, Salort M and Molodecky, N and Diop, O and Chenoweth, P and Bandyopadhyay, A and Zaffran, M and Sutter, R and Grassly, N},
doi = {10.1056/NEJMoa1716677},
journal = {New England Journal of Medicine},
pages = {834--845},
title = {Type 2 Poliovirus Detection After Global Withdrawal of Trivalent Oral Vaccine},
url = {},
volume = {379},
year = {2018}

RIS format (EndNote, RefMan)

AB - BackgroundMass campaigns with oral poliovirus vaccine (OPV) have brought the world close to the eradication of wild poliovirus. However, to complete eradication, OPV must itself be withdrawn to prevent outbreaks of vaccine-derived poliovirus (VDPV). Synchronized global withdrawal of OPV began with serotype 2 OPV (OPV2) in April 2016, which presented the first test of the feasibility of eradicating all polioviruses.MethodsWe analyzed global surveillance data on the detection of serotype 2 Sabin vaccine (Sabin-2) poliovirus and serotype 2 vaccine–derived poliovirus (VDPV2, defined as vaccine strains that are at least 0.6% divergent from Sabin-2 poliovirus in the viral protein 1 genomic region) in stool samples from 495,035 children with acute flaccid paralysis in 118 countries and in 8528 sewage samples from four countries at high risk for transmission; the samples were collected from January 1, 2013, through July 11, 2018. We used Bayesian spatiotemporal smoothing and logistic regression to identify and map risk factors for persistent detection of Sabin-2 poliovirus and VDPV2.ResultsThe prevalence of Sabin-2 poliovirus in stool samples declined from 3.9% (95% confidence interval [CI], 3.5 to 4.3) at the time of OPV2 withdrawal to 0.2% (95% CI, 0.1 to 2.7) at 2 months after withdrawal, and the detection rate in sewage samples declined from 71.0% (95% CI, 61.0 to 80.0) to 13.0% (95% CI, 8.0 to 20.0) during the same period. However, 12 months after OPV2 withdrawal, Sabin-2 poliovirus continued to be detected in stool samples (<0.1%; 95% CI, <0.1 to 0.1) and sewage samples (8.0%; 95% CI, 5.0 to 13.0) because of the use of OPV2 in response to VDPV2 outbreaks. Nine outbreaks were reported after OPV2 withdrawal and were associated with low coverage of routine immunization (odds ratio, 1.64 [95% CI, 1.14 to 2.54] per 10% absolute decrease) and low levels of population immunity (odds ratio, 2.60 [95% CI, 1.35 to 5.59] per 10% absolute decrease) within affected cou
AU - Blake,IM
AU - Pons,Salort M
AU - Molodecky,N
AU - Diop,O
AU - Chenoweth,P
AU - Bandyopadhyay,A
AU - Zaffran,M
AU - Sutter,R
AU - Grassly,N
DO - 10.1056/NEJMoa1716677
EP - 845
PY - 2018///
SN - 0028-4793
SP - 834
TI - Type 2 Poliovirus Detection After Global Withdrawal of Trivalent Oral Vaccine
T2 - New England Journal of Medicine
UR -
UR -
VL - 379
ER -