Immunization coverage among children aged 12-23 months: A cross sectional study in low performing blocks of Bihar, India.

INTRODUCTION: Immunization is one of the most cost-effective measures in public health to date, preventing at an approximately 2 to 3 million fatalities in young children every year. As per recent World Health Organisation (WHO) bulletin, these lifesaving vaccines have been successfully averted around 20 million premature deaths and 500 million disease cases. Inspite of this progress the routine vaccine coverage is slow to rise as challenges still live for the underserved, inaccessible and vulnerable children. It is therefore essential to evaluate the coverage of immunization at periodic intervals and to take the required measures to enhance the vaccination status in the State Bihar. AIMS AND
OBJECTIVE: This study aims to find out the vaccination coverage in different Blocks of study area.
MATERIAL AND METHODS: The study was community based cross sectional study which was conducted between January to March 2019 in the selected villages of 59 low performing blocks of Bihar. The study subjects were all the children aged 12-23 month old from selected low performing blocks of the Bihar. Results-Corrected FIC of the study was 90.85%. Close to nine percent (8.8%) children thou have started vaccination could not able to complete it. Rest of the beneficiaries are completely left out. The most common reason for incomplete immunization was unavailability of child on the day of vaccination followed by sickness of the child.
CONCLUSION: The overall Immunization coverage of Bihar is less than the National Immunization coverage as per NFHS-4. This study shows higher rate of immunization as far as Corrected Immunization Coverage is concerned. Copyright:

Background

Immunization is one of the most cost-effective measures in public health to date, preventing at an approximately 2--3 million fatalities in young children every year.[123] The number of deaths caused by traditional vaccine-preventable diseases (diphtheria, measles, neonatal tetanus, pertussis, and poliomyelitis) has fallen from an estimated 0.9 million in 2000 to 0.4 million in 2010.[4] Besides reducing mortality and morbidity, there is reduction in disability burden by 9 million cases and 960 million disability adjusted life years have been saved from 2001 due to this protective measure. Since 2001, the economic advantage would be around US$ 350 billion (uncertainty range: 260–460 billion), the total cost saved due to avoidance of illness. Among these costs, about US$ 250 billion (uncertainty range: 190-330 billion) had been averted since 2011.[5]

Globally, the immunization coverage rate is witnessing an increasing trend, this rate of diphtheria pertussis and tetanus-3 (DPT-3) vaccine has been increased to 85% in 2017 from 72% in 2000 and 21% in 1980.[67] According to the joint report of the World Health Organization and the United Nations International Children's Fund in 2017, the immunization coverage in South East Asia Region (SEAR) for DPT-3 is 88% and for measles containing vaccine is 87%. Maldives has recorded the highest immunization coverage (99%) in this region and Indonesia has the lowest (79%) while India lies in the intermediate category (88%).[8]

In India, this Universal Immunization Program (UIP) is the largest in the world with annual cohorts of around 26.7 million infants and 30 million pregnant women.[9] The National Family Health Survey-4 (NFHS-4) 2015--2016 reports 62% of children aged 12--23 months were completely immunized in India (BCG, 3 doses of DPT, OPV, and one dose of measles each). As per this national survey, 61.3% and 63.9% children of 12--23 months age have been fully immunized in rural areas and urban areas of India, respectively. Puducherry has the highest (91.3%) and Nagaland has the lowest (35.7%) percentage in terms of immunization coverage while immunization coverage for Uttar Pradesh, Bihar, and Jharkhand were 51.1%, 61.7%, and 61.9%, respectively.[10]

According to a Survey in Lakhisarai district, Bihar, carried out “between” 2007 and 2008, the immunization coverage was found out to be just 36.6%.[11] A decade after, NFHS-4 report had shown an improving immunization trend of Bihar (61.7%) but was found to be below national level percentage (62%). It is therefore essential to evaluate the coverage of immunization at periodic intervals and to take the required measures to enhance the vaccination status in the state of Bihar. Ethical approval obtained on 28/09/2018.

Objective

Primary

To find out the full immunization coverage, crude, and valid coverage of routine immunization among children in age group 12--23 months of age in selected parts of Bihar.

To estimate the immunization leftout and dropout and utilization of healthcare facilities by the respondents in the designated area.

Secondary

To find out the factors for partial vaccination and no vaccination in study area as opined by the respondent.

Material and Methods

This community-based cross-sectional study was conducted between January and March 2019 in the selected villages of 59 low performing blocks of Bihar. The blocks where the estimated vaccine coverage is found to be less than 70% are being taken into account. The study subjects are all the children aged 12--23 months old from those low performing blocks of Bihar.

Inclusion criteria

All the children within the 12--23 months of age who are living in the low performing blocks of Bihar.

Exclusion criteria

Children not accompanied by parents or caretaker at the time of three consecutive visit are being excluded from the study. The study respondents whose parents refused or denied to be a part of the study are excluded.

Sample size

In this study, total 59 low performing block was selected. From each block, 30 villages (clusters) and from each village 7 household was selected as per World Health Organization (WHO) protocol. Hence, the calculated sample size is found out to be 12,390 (30 × 7× 59).

Sampling procedure

The study was conducted in 59 low performing blocks (blocks with full immunization coverage was less than 70%) of Bihar. From each block, 30 villages are selected by probability proportional to size (PPS) method. In each block, the first village was selected randomly and the rest 29 villages were selected by using sampling interval being added to the cumulative total. For selection of households in each village (Cluster), a landmark (temple, mosque, Govt. building) was ascertained in the center of village, a convention of sticking to the left side was followed, and the house was selected by random selection method (currency method) and remaining household was obtained by adding the house order to the previous house number.

The data utilized for house order calculation are as follows:

Birth rate of Bihar: 26.8/1,000 population (SRS-2017)21

Infant mortality rate of Bihar: 48/1,000 Live Birth (NFHS-4)22

Average family size of Bihar: 5.5 (Census 2011)23

The study protocol was developed and tested by the Department of Community and Family Medicine, AIIMS Patna.

Study tool and personnel

Data was collected by using structured WHO coverage evaluation format. This format was later utilized in development of the web-based application Siddha Development Research and Consultancy application (SDRC app). Pretesting of the questionnaire and application was carried out before data collection. Necessary modification have been done in the application after pretesting. The data was collected by the team of data collector recruited and trained by the Dept. of CFM AIIMS Patna.

The capacity building of the field staffs in form of training includes their knowledge about vaccination schedule, methods of survey, hands on training on SDRC app in the field.

Data quality control

For the quality control, all the data collector were asked to submit daily report and the global positioning system (GPS) location of household and photograph of child to the research center, AIIMS.

Data processing and analysis

The data was cleaned and analyzed by Microsoft office Excel and Software for Statistics and Data Sciences (STATA). Descriptive statistics like frequency and percentage were used to summarize the sociodemographic characteristics of the study participants, place for vaccination, immunization coverage, dropout and leftouts.

The operational definitions of full immunization coverage (FIC), crude coverage, valid coverage and corrected full immunization coverage are being used for this research are as per WHO Guidelines.[12]

Result

After data cleaning and removal of incomplete, inconsistent, and duplicate data, the number has been reduced to 12,331 upon which all analysis have been performed.

Table 1 shows the demographic details of the study respondents. Among all (N = 12,331) male children contribute 53.31% and female children contribute 46.69%. As per religion, Hindus (81.67%) are more than Muslims (18.29%), while children from other religions are constituting a very less portion (0.04%) of the total. More than half of the0000 children belonging from the OBC caste (53.56%), followed by SC (26.86%), General (13.34%), and ST (3.67%).

Table 1

Demographic details of 59 low performing blocks of Bihar

Variables	Number (n=12,331)	Percentage (%)
Gender
Male	6,574	53.31
Female	5,757	46.69
Religion
Hindu	10,071	81.67
Muslim	2,255	18.29
Others	5	0.04
Caste
General	1,645	13.34
OBC	6,605	53.56
SC	3,312	26.86
ST	453	3.67
Others	316	2.56

OBC- Other Backward Class, SC- Scheduled Caste, ST- Scheduled Tribe

According to Table 2 in present study, 11,203 number of children out of 12,331 constituting 90.85% children are fully immunized till the date of survey. Close to 9% (8.8%) children though have started vaccination could not complete it. Rest 0.35% of the beneficiaries are completely leftout.

Table 2

Immunization status in 59 low performing Blocks of Bihar

Immunization status	Number of Children (n=12,331)	Percentage (%)
Fully Immunized	11,203	90.85%
Partially Immunized (Dropout)	1,084	8.8%
Unimmunized (Leftout)	44	0.35%

Table 3 denotes that more than 90% children are fully vaccinated.

Table 3

The Corrected Full Immunization Coverage in 59 low performing Blocks of Bihar

Full Immunization Coverage (FIC)	Total Number (n=12,331)	Lower limit of CI	Upper limit of CI
BCG + 3 Penta + 3OPV + Measles	11,203 (90.85%)	90.3	91.4

Table 4 depicts the corrected immunization coverage by each vaccine for all the beneficiaries. It is maximum across BCG (99.04%) antigen with confidence limit from 99.40% to 99.35% and minimum for the newly introduced pneumococcal vaccine PCV-2 (42.24%) with confidence limit from 41.37% to 43.11%.

Table 4

Corrected Full immunization coverage for each antigen with Confidence limit

Name of Vaccine	Immunization coverage in Percentage	Lower limit of CI	Upper limit of CI
BCG	99.21	99.04	99.35
Penta1	98.60	98.37	98.79
Penta2	97.36	97.07	97.63
Penta3	96.16	95.80	96.48
FIPV1	89.66	89.11	90.19
FIPV2	83.81	83.15	84.45
OPV1	98.43	98.20	98.64
OPV2	97.33	97.03	97.60
OPV3	95.86	95.49	96.19
PCV1	43.54	42.67	44.42
PCV2	42.24	41.37	43.11
Measles	92.52	92.05	92.97

Figure 1 showes that the total corrected full immunization coverage in the study area was found to be more than 90% with confidence interval from 90.3% to 90.4%. All 59 blocks showed FIC more than the state average (61.7%). The Bijaypur block from Gopalganj district, Aliganj block from Jamui district, and Muzzafarpur urban block are found in top position with FIC 100% (95% CI 98.2%-100%), while Jokhihat block from Araria district is showing the lowest FIC (69%). More than 90% FIC is seen in 36 blocks.

Figure 1

Corrected FIC Block wise among all 59 selected blocks

Table 5 shows crude and valid coverage for each vaccine. Highest crude and valid coverage is seen with BCG (97.82% and 82.95%), followed by pentavalent vaccine (crude coverage >90% and valid coverage >80%). For OPV 1st, 2nd, and 3rd dose the crude coverage is more than 90% and valid coverage is around 80%. However, for measles vaccine, crude coverage and valid coverage is 79.56% and 77.05%, respectively. The lowest coverage is seen for pneumococcal vaccine.

Table 5

Crude and Valid coverage for each Vaccine

Vaccine	Crude Coverage by the time of survey) (Number and Percentage)	Crude Coverage by the age of 12 month (Number and Percentage)	Valid Coverage by age the of 12 month (Number and Percentage)
BCG	12, 234 (99.21)	12,063 (97.82)	10,229 (82.95)
Penta1	12,158 (98.60)	11,527 (93.48)	9,844 (79.83)
Penta2	12006 (97.36)	11,531 (93.51)	9,944 (80.64)
Penta3	11,857 (96.16)	11,194 (90.78)	9,877 (80.09)
FIPV1	11,056 (89.66)	10,502 (85.17)	8,973 (72.76)
FIPV2	10,335 (83.81)	9,568 (77.60)	8,707 (70.61)
OPV1	12,138 (98.43)	11,442 (92.79)	9,782 (79.32)
OPV2	12002 (97.33)	11,495 (93.22)	9,927 (80.50)
OPV3	11,820 (95.86)	11,144 (90.40)	9,950 (80.69)
PCV1	5,369 (43.54)	4,500 (36.49)	3,777 (30.63)
PCV2	5208 (42.24)	4,284 (34.74)	3,757 (30.46)
Measles	11,409 (92.52)	9,810 (79.56)	9,502 (77.05)

Total Number ofchildren-12,331

Table 6 shows the dropout rate for various vaccines. Dropout rate from BCG to pentavalent 1 is very less (0.61%) while it is maximum for BCG to measles (6.68%). Dropout rate from peantavalent 1 to pentavalent 3 and pentavalent 3 to measles is 2.43% and 3.46%, respectively.

Table 6

Dropout rate for various vaccine

Vaccine	Fall in Percentage	Dropout percentage
BCG to Pentavalent 1	99.21 to 98.60	0.61%
Pentavalent 1 to Pentavalent 3	98.60 to 96.16	2.43%
Pentavalent 3 to Measles	96.16 to 92.52	3.64%
BCG to Measles	99.21 to 92.52	6.68%

According to Table 7, among all immunization sessions, most of the immunization (95.56%) takes place in Government set up and only 3.54% immunization has taken in private setup. It demonstrates that the child caregivers are well driven toward public health facilities than that of private health delivery points.

Table 7

Health Care Utilization of the respondents

Parameters of Healthcare Utilization	Number	Percentage (%)
Hospital (Govt. and Private) Delivery	9,995	81.06
Vaccination at Govt. Hospital	11,747	95.26
Vaccination at private Hospital	437	3.54
Vaccination at both (Govt and private)	147	1.20
Availability of Vaccination Card	10,372	84.11

Total Number of children-12,331

The respondents were enquired about the reasons for partial or nonimmunization as an open- ended question. The main reason cited by most of the respondents was as follows [Figure 2]: 307 out of 1,128 was unavailability of child on the day of vaccination followed by sickness. In 219 cases, the parents did not take the child for vaccination and in 68 cases the vaccinator did not give the vaccine. Lack of information about vaccination (194), fear of AEFI (131), and negative report in media about immunization (15) were also cited as main reasons of non-vaccination. Only 53 respondents cited unavailability of vaccine as the reason for non-vaccination. Similarly, only 13 respondents stated that the session time was either inconvenient or waiting time was long.

Figure 2

Reasons of partial/nonimmunization among respondents

Discussion

In our study, the corrected percentage of full immunization is found to be 90.85%. However, this coverage shows percent of beneficiaries who have taken all vaccines till the date of survey which is more than that of the NFHS-4 report of Bihar.[13] This increase possibly could be the active involvement of all stakeholders at survey level area in increasing awareness generation. The increase in FIC from 2008 (DLHS-3) till 2019 could be seen by the following diagram [Figure 3] which demonstrates promising result in the state.[14]

Figure 3

Comparison of FIC from different sources from 2009 to 2019

The full immunization coverage of children in other studies across the country reveals a similar pattern. Research conducted by Naveen et al. in tribal area of Parol, Thane district Maharashtra FIC was found to be 71.1%,[15] Murhekar et al. from Tamil Nadu reported FIC to be 79.9%,[16] Datta et al. in rural area of Tripura had highlighted it as 91.67%.[17] Another focal study from Surajgarha Block, Lakhisarai district by Kumar et al. in Bihar was 55.2%,[11] and in rural Uttar Pradesh it was 50% as per Ahmad et al.[18] The full immunization coverage is much lower in the studies from Bihar and Uttar Pradesh and this may be attributed by the lower awareness level and less health services utilization in both the territories. In this study, the valid immunization coverage was 82.95% which is comparable to the study by Murhekar et al. in Tamil Nadu, where it was 78.8%[16] and 79.4% as per the study by M. Joy et al. in Kochi, Kerala.[19]

The dropout rate in this research from BCG to pentavalent 1, BCG to measles, pentavalent-1 to pentavalent-3, and pentavalent-3 to measles is 0.61%, 6.68%, 2.43%, and 3.46%, respectively. Hence the highest dropout rate has been observed across the BCG to measles antigen (6.68%). As per the work done in Tamil Nadu by Murhekar et al., the dropout rate from BCG to measles, pentavalent 1 to measles, and pentavalent-1 to pentavalent-3 was 15.9%, 12.9%, and 4.1%, respectively.[16] Comparatively it can be stated that the dropout rate found in this study is better than that of Tamil Nadu.

In the present study, the availability of immunization card is with the 84.11% of the beneficiaries on the date of survey. The vaccination card availability is for more than 80% of the children in tribal area of Parol, Thane district as per the study conducted by Naveen et al.[15] In the study conducted by Kumar et al. in Surajgarha block, the availability was 65.7%[11] and 88.4% in study executed by Kadri et al. in urban slums of Ahmedabad city.[20]

In Bihar, almost 63.8% and 55.4% of the deliveries are institutional as per NFHS4 and DLHS4, respectively.[212223] In this current research, approximately 81% of the deliveries occur in the government institutions, which as per this finding may be the contributing factor to enhanced immunization coverage, whereas institutional delivery rate is more than 90% in southern states of India.

In present study, 8.7% children have received one or more than one vaccines but did not complete their immunization till the time of survey and 0.35% children were unimmunized. The research by M. Joy et al. in Kochi, Kerala showed that 10% children were partially immunized and 1% children were unimmunized which is almost similar to our study.[19] The percentage of partially immunized (20%) and unimmunized (4%) children was slightly higher in study done in Haryana by Prinja et al.[24] Other studies conducted by Vohra et al. in Lucknow district[25] and Nath B in urban slums of Lucknow district[26] showed that lack of awareness was the major contributor for the higher dropout rate.

In present study, the main reason cited by most of the respondents was unavailability of child on the day of vaccination followed by sickness. Madhvi et al. from Kakinada, Andhra Pradesh showed that the most common reasons for partial/no immunization are ill child (27.5%), lack of knowledge about vaccination (25.12%), migration to other places with no knowledge of place and time of vaccination (17.5%).[27] A study done by Latika Nath in Haridwar, Uttarakhand,[28] Vohra et al. in Lucknow district,[25] and Nath B in urban slums of Lucknow[26] stated that low awareness was the most common reason for partial or no immunization. A study by Singhal et al. from rural area of district Tonk, Rajasthan showed the commonest reason for partial/nonimmunized was sickness 22 (36.06%) of elder sibling as a result of the previous vaccination followed by 20 (32.07%) of the sickness of beneficiary at the time of vaccination.[29]

A study by Devendra et al. in tertiary care hospital of North India showed that the common reasons for partial immunization and nonimmunization were lack of knowledge about immunization (30.3%), apprehension about side effects of vaccination (28.8%), and lack of knowledge about subsequent doses (22.09%). Other reasons were: vaccine causes sterility, vaccine was not available and vaccinator was not available.[30] Datta et al. in rural area Tripura highlighted in their research that the main reasons for low immunization is the lack of knowledge (26.7%), any illness of the child (26.7%), followed by fear of possible adverse effects (20%).[17] The consolidated Intensified Mission Indradhanush report states the reason for non-vaccination are lack of awareness (45%), apprehension about adverse events (24%), vaccine resistance (reluctance to receive the vaccine for reasons other than fear of adverse events) (11%), child travelling (8%), and programme related gaps in 4% of the respondents.[9]

Vaccination/immunization are the components of primary care and the present study done at grassroots level of 59 low performing blocks of Bihar which shows the factors like ignorance at community level, improper supply chain and logistic are some of the challenges which need to be addressed at primary care level to achieve better FIC. At glance, community preparedness can be assessed and compared in between the blocks to identify high priority areas for different stakeholders.

Conclusion

Although the overall immunization coverage of Bihar is less than the National Immunization coverage as per NFHS-4, this study shows higher rate of immunization as far as Corrected Immunization Coverage is concerned. It may be attributed by the fact that Intensified Mission Indradhanush and responsible vigilance and accountability of each stakeholders together are able to fill the earlier gaps. The higher rate of institutional deliveries (81%) as compared to earlier and continuous monitoring and supervision of the programme in the study area are some of the other factors for enhanced vaccination coverage. But, in some blocks coverage is still below than 75%, which needs further follow-up. The blocks having corrected immunization coverage (100%) may be taken as model blocks for the state to follow some of their practices. The observed dropout rate between BCG and pentavalant-1 is only 0.61%, means almost all children are taking both the vaccine. Appropriate intervention needed to decrease the dropout rate at community level. Measures should be taken to increase institutional deliveries to further high because it has a direct association between high vaccination coverage and lower leftout and dropout as found in this research.

Limitations of the study

The study is conducted in only selected low performing blocks (base line FIC ≤70%) of Bihar, hence the results obtained may not represent the entire state. Full immunization coverage in pace of corrected immunization coverage would have been a better parameter for comparison across states.

Financial support and sponsorship

United nation Health agencies, UNICEF Bihar.

Conflicts of interest

There are no conflicts of interest.