print this page

The role of research to eradicate polio in Nigeria

Nigeria, at end-2010, reported a total of 18 wild poliovirus (WPV) cases with onset of paralysis in 2010, compared to 389 WPV cases at the same time in 2009. In 2003, though Nigeria had the highest number of polio cases in the world, planned polio supplementary immunization activities (SIAs) were suspended because of questions and concerns regarding the safety of oral polio vaccine (OPV) used in Nigeria. Consequently, the number of polio cases increased to 1,122 in 2006. The significant drop to 285 polio cases in 2007 was not sustained, as in 2008, the number of cases rose to 798. But this time, the downward trend from 2009 to 2010 appears to have been sustained.1

So how has Nigeria sustained, over the past 12 months, this very low transmission of WPV? Several factors contributed, including:

• improvements in SIA quality in high-risk Local Government Areas (LGAs);
• continued and sustained engagement of political, traditional and religious leadership; and,
• closing surveillance gaps for acute flaccid paralysis (AFP).

Importantly, these factors were catalysed by the application of new research tools combined with research into - and revised application of - existing and traditional social mobilization and communication practices.

The introduction in 2006 of monovalent OPV type 1 (mOPV1) in Nigeria, was the beginning of a positive turn-around in the country’s polio eradication efforts. Jenkins et al 2, reported that the mOPV1 was four times as efficacious than the traditionally-used trivalent OPV. The continued use of mOPV1 in frequent SIAs in Nigeria resulted in the progressive decline in the number of WPV type 1 (WPV1) cases – 724 in 2008, 75 in 2009 and seven WPV1 cases in 2010 (at end- 2010). However, with an upsurge in WPV type 3 (WPV3) cases in 2009 (from 73 in 2008 to 313 in 2009), in 2010 the bivalent OPV containing both types 1 and 3 polio was introduced on the recommendation of the Advisory Committee of Poliomyelitis Eradication (ACPE) and the Nigeria Expert Review Committee on Polio Eradication and Routine Immunization (ERC).3

Equally important as the use of mOPV1 and bivalent OPV was the change in community perceptions towards vaccination, especially polio vaccination. This ensured that more susceptible children were reached with the potent and efficacious vaccines. Innovative social mobilization and communications efforts included a “re-search” into and a review of existing and traditional social mobilization and communication practices and their modification and re-application. This has contributed to correcting misconceptions about polio vaccines and led to renewed interest and acceptance of the vaccines. One such intervention is the “majigi”. “Majigi” is a public awareness programme employing the use of open air cinemas in public places; in the past, it has been an effective and popular method of educating and informing citizens on government programmes and planned activities. The practice which was much used in the pre-independence (pre-1960) era had subsequently died out. With the traditional leaders in attendance, at the “majigi” shows, communities have become better informed, not only on polio eradication, but also on other health and community development issues. The direct involvement of traditional leaders in vaccination exercises and their engagement in mobilizing their networks has resulted in a more effective participation by the people at every level of vaccination activities and other health issues. Issues concerned with patterns of non-compliance and gender specific communication interventions require further detailed studies. For example, the “majigi” still reaches primarily men. There is a need to continue studies, in collaboration with women organizations, which will provide results that can be applied to ensure that women are reached and fully engaged in polio eradication programmes and other health interventions.

To further accelerate progress towards polio eradication, Nigeria must continue to apply the results of ongoing research and studies to enhance the quality of strategies. For example, the results of the ongoing seroprevalence studies would provide useful LGA-specific results and age-related immunity profiles that could be applied to enhance and further sensitise outreach tactics. At the same time, to adopt an aggressive mop-up strategy to respond rapidly and effectively to any remaining poliovirus transmission, the programme must take advantage of another research product, the real time reverse transcriptase PCR (rRT-PCR) technique, for the rapid and reliable identification of type and location of poliovirus isolates.

1 Polio Statistics Nigeria 2006-2010.

2 Jenkins HE., Aylward RB, Gasasira A, Donnelly CA., Abanida EA., Koleosho-Adelekan T, Grassly NC. (2008) Effectiveness of Immunization against Paralytic Poliomyelitis in Nigeria
N Engl J Med 2008; 359:1666-74.

3 Report of the 19th Meeting of the Expert Review Committee (ERC) on Polio Eradication and Routine Immunization in Nigeria, Minna, 22-24 March 2010.