Imperial College London

ProfessorNicholasGrassly

Faculty of MedicineSchool of Public Health

Prof of Infectious Disease & Vaccine Epidemiology
 
 
 
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Contact

 

+44 (0)20 7594 3264n.grassly Website

 
 
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Location

 

G36Medical SchoolSt Mary's Campus

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Summary

 

Publications

Citation

BibTex format

@article{Pons-Salort:2016:10.1371/journal.pmed.100214,
author = {Pons-Salort, M and Molodecky, NA and O'Reilly, KM and Wadood, MZ and Safdar, RM and Etsano, A and Vaz, RG and Jafari, H and Grassly, NC and Blake, IM},
doi = {10.1371/journal.pmed.100214},
journal = {Plos Medicine},
title = {Population immunity against serotype-2 poliomyelitis Leading up to the global withdrawal of the oral poliovirus vaccine: spatio-temporal modelling of surveillance data},
url = {http://dx.doi.org/10.1371/journal.pmed.100214},
volume = {13},
year = {2016}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - BackgroundGlobal withdrawal of serotype-2 oral poliovirus vaccine (OPV2) took place in April 2016. This marked a milestone in global polio eradication and was a public health intervention of unprecedented scale, affecting 155 countries. Achieving high levels of serotype-2 population immunity before OPV2 withdrawal was critical to avoid subsequent outbreaks of serotype-2 vaccine-derived polioviruses (VDPV2s).Methods and FindingsIn August 2015, we estimated vaccine-induced population immunity against serotype-2 poliomyelitis for 1 January 2004–30 June 2015 and produced forecasts for April 2016 by district in Nigeria and Pakistan. Population immunity was estimated from the vaccination histories of children <36 mo old identified with non-polio acute flaccid paralysis (AFP) reported through polio surveillance, information on immunisation activities with different oral poliovirus vaccine (OPV) formulations, and serotype-specific estimates of the efficacy of these OPVs against poliomyelitis. District immunity estimates were spatio-temporally smoothed using a Bayesian hierarchical framework. Coverage estimates for immunisation activities were also obtained, allowing for heterogeneity within and among districts. Forward projections of immunity, based on these estimates and planned immunisation activities, were produced through to April 2016 using a cohort model.Estimated population immunity was negatively correlated with the probability of VDPV2 poliomyelitis being reported in a district. In Nigeria and Pakistan, declines in immunity during 2008–2009 and 2012–2013, respectively, were associated with outbreaks of VDPV2. Immunity has since improved in both countries as a result of increased use of trivalent OPV, and projections generally indicated sustained or improved immunity in April 2016, such that the majority of districts (99% [95% uncertainty interval 97%–100%] in Nigeria and 84% [95% uncertainty interval 77%–91%] in Pakistan) had >70
AU - Pons-Salort,M
AU - Molodecky,NA
AU - O'Reilly,KM
AU - Wadood,MZ
AU - Safdar,RM
AU - Etsano,A
AU - Vaz,RG
AU - Jafari,H
AU - Grassly,NC
AU - Blake,IM
DO - 10.1371/journal.pmed.100214
PY - 2016///
SN - 1549-1676
TI - Population immunity against serotype-2 poliomyelitis Leading up to the global withdrawal of the oral poliovirus vaccine: spatio-temporal modelling of surveillance data
T2 - Plos Medicine
UR - http://dx.doi.org/10.1371/journal.pmed.100214
UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000387656000004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
UR - http://hdl.handle.net/10044/1/41097
VL - 13
ER -