Assessment of Immunization Coverage and its Determinants Amongst Children in an Urban Area. Study Protocol of a Cross Sectional Study

Background

The first line of defence against disease has been described as immunization, which is also one of the best health benefits available to children.¹ Vaccines have the biggest success stories in the field of public health. Globally, childhood immunization against vaccine-preventable diseases (VPD) is acknowledged as one of the most affordable initiatives to reduce childhood fatalities and morbidities.² Each year, it saves millions of lives worldwide and averts crippling disease and disability.³ The challenge of low immunization coverage is pervasive, affecting urban slum populations to a similar extent as remote rural areas. According to an initial scenario based on projected proportions of unimmunized children in both rural and urban areas, indicates that nearly half (44%) of the unimmunized and under-immunized children in the top 10 nations, which collectively housed over half of such children in 2017, resided in urban areas. Notably, nearly every fifth unimmunized child (18%) was found to live in a slum, highlighting the specific vulnerability of these urban environments in terms of immunization coverage.⁴

Since 1974, the World Health Organization (WHO) - supported Expanded Programme on Immunization (EPI) has played a pivotal role in significantly increasing global access to vaccines. A noteworthy decline in the number of childhood illnesses that can be prevented and fatalities has been achieved for the six vaccine-preventable diseases (VPDs) initially targeted. These diseases include tuberculosis, diphtheria, pertussis, tetanus, measles, and poliomyelitis. The success in the early years of the program demonstrates the effectiveness of vaccination efforts in curbing the impact of these serious diseases on child health and mortality. The Universal Immunization Programme (UIP) was introduced in 1985 by the Government of India (GOI), which expedited its own EPI (started in 1978) with the goal of reaching a target coverage of 90% by 1990. Every year, the UIP provides care for nearly 26 million infants and 125 million children under the age of five.⁵

Despite the ongoing awareness campaigns and concerted efforts in India’s immunization program, the coverage of immunization for children continues to fall short of the targets set by the Universal Immunization Program (UIP).¹ Over the past few decades, India’s urban population has grown dramatically, making up approximately one-third of the nation’s total population. The population projections suggest that by the year 2045, approximately 800 million individuals in India will be residing in urban areas.⁶ According to a recent NFHS-5 survey based on information from vaccination cards or mother memory, in India 62.0% the percentage of children aged 12-23 months are fully vaccinated, and in urban areas, it is only 75.5%. Furthermore, based solely on information from vaccination cards, the percentage of children in India between the ages of 12 and 23 months who are fully vaccinated is 77.9% nationwide, and 83.3% in urban areas.⁷ The reach of the public sector urban health delivery system has been constrained, and its adequacy remains significantly lacking.⁶ Reaching Children Full Immunization (CFI) would achieve Sustainable Development Goal 3 (SDG 3) goal 3.2 and ensure a decrease in childhood mortality.⁸

By effectively using vaccinations, the majority of affluent countries have decreased the occurrence of diseases that can be prevented by vaccines.⁹ The current health delivery system is still unable to meet the demands of the urban poor population. Less than 4% of India’s government primary healthcare facilities are located in metropolitan regions. Our study will highlight a need for government to pay attention to poor health services.¹⁰

In the scope of this study, our primary focus will be on evaluating immunization coverage. This assessment is crucial for strategic planning of immunization programs, pinpointing vulnerable groups that necessitate targeted resource allocation, and forecasting potential epidemics of vaccine-preventable diseases. By conducting this evaluation, we aim to contribute valuable insights that can inform and enhance public health initiatives related to immunization.⁶

Urban slums may have poor coverage rates because, unlike rural regions where immunization services are given at the village level, urban communities still primarily receive them in clinical or hospital settings.¹¹ In Low and Middle Income Countries (LMICs), household income and social standing, parental awareness, and religious and cultural attitudes are significant demand-side drivers of child vaccination coverage. In terms of supply-side variables, distance to the immunization session site, poor service quality, and a lack of facility resources are known causes of children not receiving vaccinations.¹² In order to accommodate the expanding urban population, it is necessary to improve the urban infrastructure for health at all scales, including large cities and small villages.¹¹

By reducing the number of cases, reducing the clustering of cases within households, and lengthening the period between outbreaks, immunization programs in urban settings can have a major impact on the mortality associated with vaccine preventable disease.¹³ In the low-income states with the largest birth cohorts, the government might also train and reward a greater range of private-sector health workers to assist in administering the immunizations.⁵ When immunization is a priority for urban health, EPI administrators must identify special initiatives for disease prevention in cities.¹⁴ In order to ensure that vaccinations and their administration are suitable, sustainable, and acceptable, it is imperative that communities and civil society be included. In order to break down social and cultural barriers, restore lost trust in vaccination programs, and promote the locally appropriate use of vaccines, community-based organizations have increased their involvement in immunization efforts.⁴

Rationale

Assessing the overall immunization coverage rate for children in the urban area is crucial for understanding the level of protection against vaccine-preventable diseases. This information helps identify gaps in vaccination coverage and formulate targeted interventions to improve immunization rates and public health outcomes. While previous research has exhaustively documented the elements that affect immunization demand in India, the association between children immunization outcomes in low-income countries and the accessibility of health facilities has not yet been thoroughly examined. In this study, we will also be assessing the immunisation coverage and its determinants amongst children in an urban area.

Aim

Assessment of immunisation coverage and its determinants, amongst children (0-23 months) in the urban area of the Wardha district.

Objectives

Study design

This study will be cross-sectional in nature.

Study place/setting

The study will be carried in School of Epidemiology and Public Health urban field practice area, DMIHER, Wardha.

Study duration

The study will be carried out between November 2023 and May 2024.

Study participants/population

The interpersonal questions about vaccination will be asked to the parents of 0-23 month children. The parents will be asked whether they have their immunization cards with complete immunization of their children. This study will include the children ages 0-23 months living in urban areas. Children ages more than 23 months and living in rural areas will be excluded from the study.

Inclusion criteria

Exclusion criteria

Sample size

To calculate the required sample size we used

Estimate a proportion with absolute precision

Alpha (a) 0.05

Estimated proportion (p) 0.62

Estimated error (d) 0.05

CALCULATE

Minimum sample size needed: 363

Sampling method

The present study will be conducted using convenient sampling method.

Variables

In this study, we will scrutinize variables related to demographic information and the accessibility and proximity of participants to health centres offering comprehensive immunization services. This examination aims to understand and analyze the potential impact of demographic factors and the availability of nearby health facilities on the immunization patterns observed in the study population. Table 1 elaborates the variables related to immunization coverage.¹⁰

Data collection procedure

A semi-structured questionnaire with the following two sections will be used to gather information:

Section A: Sociodemographic information of the participants. Sex, Birth order, Age of child, Mothers education, Mother’s occupation, Mother’s age, Religion of household, Social category.

Section B: Other determinants associated with immunization coverage.

Government UHC, Government hospital, Private clinic/hospital, Private provider, AWC, NGOs.

The questionnaire will be translated to the local vernacular language Marathi.

Bias

The absence of a comprehensive sampling frame and reliance on convenience sampling may compromise the representativeness of the obtained sample, thereby hindering the ability to draw meaningful generalizations to the broader population under investigation. Additionally, the survey may be susceptible to biases, as respondents might selectively provide answers, introducing potential distortions in the data. Furthermore, the lack of detailed information regarding immunization status could introduce recall bias, further complicating the accuracy and reliability of the study findings.

Analysis plan and expected results

The data collected will be entered into a Microsoft Excel sheet and subsequently analyzed using the Statistical Package for the Social Sciences (SPSS), version 27 https://www.ibm.com/support/pages/node/1101369 as an alternative we will use R software R: The R Project for Statistical Computing (r-project.org). Then analysed data will be tabulated in the form of tables. The classification of children’s immunization status in this study will be based on specific criteria. A child will be considered to have a “complete” immunization status if they have acquired 1 dose of the BCG vaccine, 3 doses each of diphtheria, pertussis, and tetanus (DPT3) vaccines, along with oral polio vaccines, and 1 dose of the measles vaccine. Conversely, if any one or more of these vaccines will be missing, the child’s immunization status will be labelled as “partial.” Conversely, if the child has not received any vaccines, their status will be classified as “not” immunized. This classification system provides a comprehensive framework for assessing the extent of immunization coverage among the study participants.

Dissemination

The study protocol will be publish in indexed journal and will be presented in seminars and conference.

Study status

The study has been started after getting approval from the IEC department of DMIHER (DU) and is under process.

Study implications

This study aims to assess the current immunization status of participants. Additionally, the gathered data holds the potential for application in future studies. By conducting this research, valuable insights into the barriers to child immunization in urban areas can be gained, allowing for the identification of measures to overcome these challenges.

Limitations

It is important to acknowledge that this study is limited to its scope, as it does not encompass the assessment of the healthcare worker’s or healthcare facility’s service quality. The quality of services is a crucial aspect that can influence both cost and coverage. Additionally, it plays a significant role in determining the cost-effectiveness of expanding Universal Health Coverage (UHC) and the functions of Integrated Child Development Services (ICDS). Finally, since the study will be limited to one Indian region, it will be necessary to see whether it can be generalized to other Indian towns and other nations.