IRUS Total

Type 2 Poliovirus Detection After Global Withdrawal of Trivalent Oral Vaccine

File Description SizeFormat 
nejmoa1716677(1).pdfPublished version1.06 MBAdobe PDFView/Open
Title: Type 2 Poliovirus Detection After Global Withdrawal of Trivalent Oral Vaccine
Authors: Blake, IM
Pons Salort, M
Molodecky, N
Diop, O
Chenoweth, P
Bandyopadhyay, A
Zaffran, M
Sutter, R
Grassly, N
Item Type: Journal Article
Abstract: Background Mass 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 However, to complete eradication, OPV must itself be withdrawn to prevent outbreaks of vaccine-derived poliovirus (VDPV).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. Methods We 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. Results The 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 countries. Conclusions High population immunity has facilitated the decline in the prevalence of Sabin-2 poliovirus after OPV2 withdrawal and restricted the circulation of VDPV2 to areas known to be at high risk for transmission. The prevention of VDPV2 outbreaks in these known areas before the accumulation of substantial cohorts of children susceptible to type 2 poliovirus remains a high priority.
Issue Date: 30-Aug-2018
Date of Acceptance: 3-May-2018
URI: http://hdl.handle.net/10044/1/61957
DOI: https://dx.doi.org/10.1056/NEJMoa1716677
ISSN: 0028-4793
Publisher: Massachusetts Medical Society
Start Page: 834
End Page: 845
Journal / Book Title: New England Journal of Medicine
Volume: 379
Issue: 9
Copyright Statement: © 2018 Massachusetts Medical Society. All rights reserved.
Sponsor/Funder: Bill & Melinda Gates Foundation
Medical Research Council (MRC)
Bill & Melinda Gates Foundation
World Health Organization (Switzerland)
Funder's Grant Number: OPP1099374
Keywords: 11 Medical And Health Sciences
General & Internal Medicine
Publication Status: Published
Open Access location: https://www.nejm.org/doi/full/10.1056/NEJMoa1716677
Online Publication Date: 2018-08-30
Appears in Collections:School of Public Health