University of North Carolina Charlotte (Olorunsaiye); University of Hull (Degge)
Globally, immunisation prevents an estimated 2–3 million deaths among under-5 children, yet in Nigeria, only 25% of children ages 12–23 months are fully immunised. There are also marked disparities in the uptake of immunisations, largely attributable to the context within which families live and seek health care. The authors assessed the individual and state determinants of child immunisation in Nigeria and used multilevel logistic regression to estimate the odds of full immunisation among 5,561 children aged 12–23 months, with their mothers clustered in the 36 states and the Federal Capital Territory (level 2). The idea is that identifying the determinants of spatial variations in immunisation uptake in Nigeria could contribute to identifying underserved areas, developing appropriate targeted strategies for interventions to improve the utilisation of immunisation services, and providing evidence for the judicious allocation of public health funds for successful structural and individual behaviour change.
The paper examines the state of immunisation in Nigeria, describing, for example, the 2003 polio vaccination boycott in 3 northern states that contributed to the reintroduction of the wild polio virus (WPV) into 31 countries that were previously polio free. Despite these and other setbacks, Nigeria was declared polio free in September 2015, and as of the publication of this article, has not had a single case of WPV since July 2014. Nevertheless, concerted efforts are still required to ensure polio does not reemerge and to have the African region certified polio free in 2018. As noted here, a fully immunised child ages 12–23 months in Nigeria is expected to have received 1 dose of Bacillus Calmette–Guérin (BCG) at birth or soon after, 3 doses each of diphtheria, pertussis, and tetanus (DPT) and oral polio vaccine (OPV) vaccines at 6, 10, and 14 weeks, and 1 dose of measles vaccine at 9 months or soon after.
Data for this study were drawn from the 2013 Nigeria Demographic and Health Survey (DHS). The researchers used data from the women's questionnaire. A total of 38,948 women between 15 to 49 years old were interviewed, of whom 16,426 reported recent live births within the 3 years preceding the survey. Most women included in this study had no formal education (48.5%), and were in the economically poorest (23.4%) or poorer (22.7%) wealth quintiles. In addition, the highest proportion of women were Muslim (61.4%) and employed in nonprofessional occupations (67.4%). Nearly two-thirds of the women (64.6%) lived in rural areas.
Findings indicate low immunisation coverage rates overall: DPT1 (first dose) = 49.8%, DPT3 = 38.2%, measles = 41.8%, and full immunisation = 24.9%. Approximately 1 in 5 children was unimmunised (20.9%). Comparatively, the proportion of fully immunised children ages 12–23 months in Nigeria is lower than in other neighbouring countries (Benin: 43%; Cameroun: 53%; Ghana: 77%; Niger: 52%; and Togo: 62%). There was significant clustering of full immunisation at the state level (31%, p < .001), and there were marked variations among states in the percentage of fully immunised children, ranging from 1% in Sokoto State to nearly 63% in Imo State. "[T]he above average clusters of unimmunized children in the northeast are not surprising. For several years, many states in the northeast of the country have experienced series of armed conflicts and attacks on communities and health care workers by the fundamentalist group, Boko Haram, which may possibly explain the extremely high proportions of unimmunized children in these states (Borno: 73.2%, Yobe: 64.8%, Gombe: 52.3%, and Bauchi: 43.7%)."
The authors found that having a health card and receiving postnatal care within the first 2 months of life were positively associated with full immunisation, as were maternal education, wealth, age, and ethnicity. ("Educated mothers are more likely to comprehend health information and to be aware of the availability and benefits of child immunization....[Yet, c]ontrary to our expectation, there was no association between female literacy at the state level and child immunization.") At the state level, the proportion of employed mothers and those who received tetanus immunisation before birth was positively associated with full immunisation. The following barriers were negatively associated with full immunisation: needing to obtain permission, poor financial situation, and far distance to clinic. Muslim religious affiliation was associated with reduced odds of full immunisation. "The free immunization policy in the country may not be enough to ensure equitable access and use of these services."
"After accounting for child, maternal sociodemographic and state socioeconomic characteristics, the state variance in child immunization status decreased but remained statistically significant, suggesting substantial variations in access to, and use of, immunization services among states....These findings call for state-specific targeting to address inequitable access to routine immunization in Nigeria."
The authors conclude that, "[a]s the second tier of government in Nigeria, states occupy a strategic position in policy making, and we hope that these findings will inform planning and implementing programs aimed at improving immunization uptake, and closing the equity gap in access to routine immunizations. Going forward, further research into vaccine supply and availability of immunization services will be very helpful in identifying supply side barriers to full immunization among states. Furthermore, qualitative or mixed methods study design would provide an understanding of contextual barriers and social norms affecting immunization that are not measured in the prevalent quantitative surveys, and provide evidence for education and behavior change communication for childhood immunizations."
Editor's note: This paper has been published as part of a United States Agency for International Development (USAID)-funded initiative to increase the number of peer-reviewed papers on routine and polio communication and to ensure that academics from a range of countries, including those facing the greatest polio and routine immunisation challenges, are supported in getting their research peer reviewed, published, and widely disseminated through The CI and the new journal Global Health Communication.
Global Health Communication, 2:1, 19-29, DOI: 10.1080/23762004.2016.1206780. Image credit: World Health Organization (WHO)/L.Dore