1.1 Introduction
Immunization is the process of protecting individuals, especially children, against infectious diseases by giving vaccines that stimulate the body to develop immunity. Child immunization is one of the most important public health measures because it helps prevent diseases such as tuberculosis, polio, measles, diphtheria, tetanus, and other vaccine-preventable illnesses. Immunization coverage refers to the proportion of eligible children who have received the recommended vaccines within a specified period. Immunization according to the World Health Organization remains one of the most successful public health interventions, although millions of children worldwide still miss essential vaccines (WHO, 2026).
In Nigeria, routine child immunization is provided mainly through primary healthcare facilities and is designed to ensure that children receive vaccines according to the national immunization schedule. Despite continued government and health-sector efforts, vaccination coverage remains uneven across the country. The Nigeria Demographic and Health Survey reported that only 39% of children aged 12–23 months were fully vaccinated against basic antigens in 2024, while 31% had received no vaccination at all (National Population Commission & ICF, 2024). Factors such as parents' education, access to health facilities, place of residence, awareness, socioeconomic conditions, and availability of vaccination services may influence whether children receive their vaccines as recommended.
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the aim and objectives of the study. Others are significance of the study, scope of work, research hypothesis and questions, limitation of the study and definition of terms.
1.2 Background of Study
Historically, child immunization dates back several centuries, when communities developed different methods of protecting people from infectious diseases. One of the earliest known practices was variolation, which involved deliberate exposure to smallpox material to provide protection against the disease. The development of modern vaccines later changed the approach to disease prevention. According to the World Health Organization (WHO, 2024), the Expanded Programme on Immunization (EPI) was launched globally in 1974 to ensure that children had access to vaccines against major childhood diseases. The original programme focused mainly on tuberculosis, diphtheria, pertussis, tetanus, polio, and measles.
Child immunization is one of the most important measures for protecting children from diseases that may cause serious illness, disability, or death. WHO and UNICEF reported that in 2025, about 90% of infants globally received at least one dose of a diphtheria, tetanus, and pertussis-containing vaccine, while about 13.5 million children received no routine vaccination at all (WHO & UNICEF, 2026). In the same vein, the presence of unvaccinated children creates opportunities for outbreaks of diseases that are otherwise preventable through routine vaccination.
In Nigeria, immunization is an important component of primary healthcare and is provided through routine services at health facilities and communities. According to the National Population Commission and ICF (2024), only 39% of Nigerian children aged 12–23 months were fully vaccinated against the basic antigens, while 31% had received no vaccination. Likewise, only 20% were fully vaccinated according to the national vaccination schedule. These figures show that a considerable proportion of Nigerian children are still not receiving all the vaccines required for adequate protection. Moreover, vaccination coverage differs considerably across states and regions, indicating that national averages may hide serious gaps at local levels. Correspondingly, Adeloye et al. (2017) reported that childhood immunization coverage in Nigeria was generally low, with particularly poor coverage in the North-west region.
Oleribe et al. (2017) reported that maternal education, household socioeconomic conditions, access to health services, and other individual characteristics influence childhood immunization coverage. In the same vein, caregivers who have limited knowledge of vaccination schedules may fail to return to the health facility when subsequent doses are due. Furthermore, distance to health facilities, transportation difficulties, long waiting times, inconvenient service schedules, vaccine availability, and competing household responsibilities may discourage regular attendance. Supporting this position, Adeloye et al. (2017) identified vaccine unavailability, safety concerns, low maternal education, and poor information as important factors associated with low immunization coverage in Nigeria.
Sabon Gari in Kano State provides an appropriate setting for examining these issues because the Primary Health Centre serves as a point of contact between caregivers and routine child immunization services. Correspondingly, assessing the vaccination status of children attending the facility may provide evidence on the extent to which recommended immunization services are being utilized. The assessment is also important because previous research has noted limited evidence from some northern parts of Nigeria, making local studies necessary for better understanding of immunization gaps (Adeloye et al., 2017).
This study is set against the backdrop of the continuing challenge of incomplete and missed childhood immunization in Nigeria, particularly the need to understand local factors that influence vaccination coverage in communities within Kano State. It is therefore necessary to evaluate the level of child immunization coverage at the Primary Health Centre, Sabon Gari, and examine the determinants that may be responsible for complete, incomplete, or missed vaccination among children attending the facility.
1.3 Statement of Problems
Investigation revealed that child immunization remains an important public health service for preventing vaccine-preventable diseases, yet some children still do not receive all the vaccines required under the routine immunization schedule. In some primary health centres, parents may miss vaccination appointments because of poor awareness, distance to health facilities, fear of side effects, or lack of adequate information. On the other hand, poor communication between health workers and caregivers may also affect parents' willingness to return for subsequent doses.
Furthermore, factors such as parents' knowledge, education, household conditions, availability of vaccines, waiting time, and accessibility of health services may influence whether children complete their immunization. It is against this backdrop that this study seeks to evaluate child immunization coverage and its determinants at the Primary Health Centre, Sabon Gari, Kano State.
1.4 Aim and Objectives of Study
The aim of this study is to evaluate child immunization coverage and determine the factors influencing immunization uptake among children attending the Primary Health Centre, Sabon Gari, Kano State.
The specific objectives of the study are to:
- Determine the level of immunization coverage among children attending the Primary Health Centre, Sabon Gari;
- Assess the knowledge of caregivers about childhood immunization;
- Identify the major factors influencing completion or non-completion of childhood immunization;
- Examine the accessibility and availability of routine immunization services at the health centre; and
- Determine the relationship between identified caregiver and health-service factors and child immunization coverage.
1.5 Research Questions
The study came up with research questions so as to be able to ascertain the above stated objectives. The study will answer the following questions:
- What is the level of immunization coverage among children attending the Primary Health Centre, Sabon Gari?
- What is the level of caregivers' knowledge about childhood immunization?
- What are the major factors influencing completion or non-completion of childhood immunization?
- How accessible and available are routine immunization services at the Primary Health Centre, Sabon Gari?
- What relationship exists between identified caregiver and health-service factors and child immunization coverage?
1.6 Research Hypotheses
In order to pursue the objective of this study, the following generalized statements have been designed to guide and aids in obtaining the result for the experiment to be conducted. For this work, the null hypothesis will be represented with H0 while the alternative hypothesis will be represented with hypothesis H1.
Hypothesis One
- H0: There is no significant relationship between caregivers' knowledge and child immunization coverage at the Primary Health Centre, Sabon Gari.
- H1: There is a significant relationship between caregivers' knowledge and child immunization coverage at the Primary Health Centre, Sabon Gari.
Hypothesis Two
- H0: There is no significant relationship between accessibility of routine immunization services and child immunization coverage at the Primary Health Centre, Sabon Gari.
- H1: There is a significant relationship between accessibility of routine immunization services and child immunization coverage at the Primary Health Centre, Sabon Gari.
Hypothesis Three
- H0: There is no significant relationship between socioeconomic factors and completion of childhood immunization among children attending the Primary Health Centre, Sabon Gari.
- H1: There is a significant relationship between socioeconomic factors and completion of childhood immunization among children attending the Primary Health Centre, Sabon Gari.
1.7 Significance of Study
The outcome of this research will provide parents and caregivers with simple information about the importance of completing their children's vaccination schedules. The study will also help health workers identify common reasons for missed vaccinations and improve communication with caregivers.
Furthermore, the study will provide the health centre with local information for monitoring immunization coverage and improving routine vaccination activities. It will also provide useful evidence for planning and strengthening childhood immunization activities within Kano State.
Lastly, the findings will provide useful academic information for future studies on immunization coverage, vaccine uptake, and child health in Nigeria.
1.8 Scope of Study
The study is limited to the evaluation of child immunization coverage and its determinants at the Primary Health Centre, Sabon Gari, Kano State, Nigeria. The scope of this research is focused on children receiving routine immunization services at the health centre and their caregivers.
The study covers vaccination status, caregivers' knowledge, accessibility of immunization services, socioeconomic factors, availability of services, and other factors that influence completion of childhood immunization. The study does not cover all health facilities in Kano State.
1.9 Limitations of the Study
During the course of this study, there were some problems encountered which stood as limitations to the research work. Some of the limitations include:
- Delay from Respondents: Some caregivers delayed in completing or returning the research questionnaire. This affected the speed of data collection and required additional follow-up.
- Financial Constraints: Limited financial resources affected transportation, printing, photocopying, and other expenses associated with the research.
- Time Constraints: The study was conducted within a limited academic period. This reduced the time available for extensive visits, follow-up, and collection of additional information.
1.10 Definition of Terms
Child:
Child is a young person who falls within the age group covered by the routine childhood immunization programme. In this study, the term refers to children whose vaccination status is assessed at the Primary Health Centre, Sabon Gari.
Immunization:
Immunization is the process of protecting a person against infectious diseases through vaccination. The World Health Organization (2024) describes immunization as one of the most successful public health interventions for preventing vaccine-preventable diseases.
Child Immunization:
Child immunization is the administration of recommended vaccines to children at specified ages to protect them against vaccine-preventable diseases such as tuberculosis, polio, measles, diphtheria, pertussis, and tetanus.
Immunization Coverage:
Immunization coverage is the proportion of eligible children who have received specified vaccines within a particular population and period. It is used to measure the level of utilization of immunization services.
Complete Immunization:
Complete immunization is the receipt of all vaccines and doses recommended for a child according to the applicable routine immunization schedule.
Incomplete Immunization:
Incomplete immunization is a situation where a child has received some recommended vaccines but has not received all the required doses.
Missed Vaccination:
Missed vaccination is the failure of a child to receive a vaccine dose at the recommended time or failure to return for a scheduled vaccination.
Routine Immunization:
Routine immunization is the regular delivery of recommended vaccines to eligible individuals through health facilities, outreach services, and other established health-service channels.
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