Analysis of vaccination campaign effectiveness and population immunity to support and sustain polio elimination in Nigeria

BMC Medicine

Research Article

Arend Voorman¹  Faisal Shuaib²  Guillaume Chabot-Couture³  Hil M. Lyons³  Alexander M. Upfill-Brown³ 

[1] Bill & Melinda Gates Foundation, Seattle, WA, USA;Federal Ministry of Health, Federal Republic of Nigeria, Abuja, FCT, Nigeria;National Polio Emergency Operations Center, Abuja, FCT, Nigeria;Institute for Disease Modeling, Bellevue, WA, USA;

关键词: Campaigns;    Coverage;    Eradication;    Hierarchical modeling;    Immunity;    Nigeria;    Polio;    Supplementary immunization activities;   

DOI  :  10.1186/s12916-016-0600-z

 received in 2015-11-14, accepted in 2016-03-12,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundThe world is closer than ever to a polio-free Africa. In this end-stage, it is important to ensure high levels of population immunity to prevent polio outbreaks. Here, we introduce a new method of assessing vaccination campaign effectiveness and estimating immunity at the district-level. We demonstrate how this approach can be used to plan the vaccination campaigns prospectively to better manage population immunity in Northern Nigeria.MethodsUsing Nigerian acute flaccid paralysis surveillance data from 2004–2014, we developed a Bayesian hierarchical model of campaign effectiveness and compared it to lot-quality assurance sampling data. We then used reconstructed sero-specific population immunity based on campaign history and compared district estimates of immunity to the occurrence of confirmed poliovirus cases.ResultsEstimated campaign effectiveness has improved across northern Nigeria since 2004, with Kano state experiencing an increase of 40 % (95 % CI, 26–54 %) in effectiveness from 2013 to 2014. Immunity to type 1 poliovirus has increased steadily. On the other hand, type 2 immunity was low and variable until the recent use of trivalent oral polio vaccine. We find that immunity estimates are related to the occurrence of both wild and vaccine-derived poliovirus cases and that campaign effectiveness correlates with direct measurements using lot-quality assurance sampling. Future campaign schedules highlight the trade-offs involved with using different vaccine types.ConclusionsThe model in this study provides a novel method for assessing vaccination campaign performance and epidemiologically-relevant estimates of population immunity. Small-area estimates of campaign effectiveness can then be used to evaluate prospective campaign plans. This modeling approach could be applied to other countries as well as other vaccine preventable diseases.

【 授权许可】

CC BY   
© Upfill-Brown et al. 2016