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Effectiveness of immunization against paralytic poliomyelitis in Nigeria.
N Engl J Med. 2008 Oct 16; 359(16):1666-74.NEJM

Abstract

BACKGROUND

The number of cases of paralytic poliomyelitis has declined in Nigeria since the introduction of newly licensed monovalent oral poliovirus vaccines and new techniques of vaccine delivery. Understanding the relative contribution of these vaccines and the improved coverage to the decline in incident cases is essential for future planning.

METHODS

We estimated the field efficacies of monovalent type 1 oral poliovirus vaccine and trivalent oral poliovirus vaccine, using the reported number of doses received by people with poliomyelitis and by matched controls as identified in Nigeria's national surveillance database, in which 27,379 cases of acute flaccid paralysis were recorded between 2001 and 2007. Our estimates of vaccine coverage and vaccine-induced immunity were based on the number of doses received by children listed in the database who had paralysis that was not caused by poliovirus.

RESULTS

The estimated efficacies per dose of monovalent type 1 oral poliovirus vaccine and trivalent oral poliovirus vaccine against type 1 paralytic poliomyelitis were 67% (95% confidence interval [CI], 39 to 82) and 16% (95% CI, 10 to 21), respectively, and the estimated efficacy per dose of trivalent oral poliovirus vaccine against type 3 paralytic poliomyelitis was 18% (95% CI, 9 to 26). In the northwestern region of Nigeria, which reported the majority of cases during the study period, coverage with at least one dose of vaccine increased from 59 to 78%. Between 2005 and 2007, vaccine-induced immunity levels among children under the age of 5 years more than doubled, to 56%.

CONCLUSIONS

The higher efficacy of monovalent type 1 oral poliovirus vaccine (four times as effective as trivalent oral poliovirus vaccine) and the moderate gains in coverage dramatically increased vaccine-induced immunity against serotype 1 in northern Nigeria. Further increases in coverage in Nigerian states with infected populations are required to achieve the levels of vaccine-induced immunity associated with the sustained elimination achieved in other parts of the country.

Authors+Show Affiliations

Medical Research Council Centre for Outbreak Analysis and Modeling, Department of Infectious Disease Epidemiology, Faculty of Medicine, Imperial College London, London, United Kingdom. h.jenkins@imperial.ac.ukNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

18923171

Citation

Jenkins, Helen E., et al. "Effectiveness of Immunization Against Paralytic Poliomyelitis in Nigeria." The New England Journal of Medicine, vol. 359, no. 16, 2008, pp. 1666-74.
Jenkins HE, Aylward RB, Gasasira A, et al. Effectiveness of immunization against paralytic poliomyelitis in Nigeria. N Engl J Med. 2008;359(16):1666-74.
Jenkins, H. E., Aylward, R. B., Gasasira, A., Donnelly, C. A., Abanida, E. A., Koleosho-Adelekan, T., & Grassly, N. C. (2008). Effectiveness of immunization against paralytic poliomyelitis in Nigeria. The New England Journal of Medicine, 359(16), 1666-74. https://doi.org/10.1056/NEJMoa0803259
Jenkins HE, et al. Effectiveness of Immunization Against Paralytic Poliomyelitis in Nigeria. N Engl J Med. 2008 Oct 16;359(16):1666-74. PubMed PMID: 18923171.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Effectiveness of immunization against paralytic poliomyelitis in Nigeria. AU - Jenkins,Helen E, AU - Aylward,R Bruce, AU - Gasasira,Alex, AU - Donnelly,Christl A, AU - Abanida,Emmanuel A, AU - Koleosho-Adelekan,Titi, AU - Grassly,Nicholas C, PY - 2008/10/17/pubmed PY - 2008/10/24/medline PY - 2008/10/17/entrez SP - 1666 EP - 74 JF - The New England journal of medicine JO - N. Engl. J. Med. VL - 359 IS - 16 N2 - BACKGROUND: The number of cases of paralytic poliomyelitis has declined in Nigeria since the introduction of newly licensed monovalent oral poliovirus vaccines and new techniques of vaccine delivery. Understanding the relative contribution of these vaccines and the improved coverage to the decline in incident cases is essential for future planning. METHODS: We estimated the field efficacies of monovalent type 1 oral poliovirus vaccine and trivalent oral poliovirus vaccine, using the reported number of doses received by people with poliomyelitis and by matched controls as identified in Nigeria's national surveillance database, in which 27,379 cases of acute flaccid paralysis were recorded between 2001 and 2007. Our estimates of vaccine coverage and vaccine-induced immunity were based on the number of doses received by children listed in the database who had paralysis that was not caused by poliovirus. RESULTS: The estimated efficacies per dose of monovalent type 1 oral poliovirus vaccine and trivalent oral poliovirus vaccine against type 1 paralytic poliomyelitis were 67% (95% confidence interval [CI], 39 to 82) and 16% (95% CI, 10 to 21), respectively, and the estimated efficacy per dose of trivalent oral poliovirus vaccine against type 3 paralytic poliomyelitis was 18% (95% CI, 9 to 26). In the northwestern region of Nigeria, which reported the majority of cases during the study period, coverage with at least one dose of vaccine increased from 59 to 78%. Between 2005 and 2007, vaccine-induced immunity levels among children under the age of 5 years more than doubled, to 56%. CONCLUSIONS: The higher efficacy of monovalent type 1 oral poliovirus vaccine (four times as effective as trivalent oral poliovirus vaccine) and the moderate gains in coverage dramatically increased vaccine-induced immunity against serotype 1 in northern Nigeria. Further increases in coverage in Nigerian states with infected populations are required to achieve the levels of vaccine-induced immunity associated with the sustained elimination achieved in other parts of the country. SN - 1533-4406 UR - https://www.unboundmedicine.com/medline/citation/18923171/full_citation L2 - http://www.nejm.org/doi/full/10.1056/NEJMoa0803259?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -