Introduction
Immunity depicts the capability of the body to resist harmful microbes from gaining access into it. It depicts the ability to develop immunity. Immunity being the state of having sufficient biological defences to avoid infection disease, or other unwanted biological invasion [1]. Immunization is the process by which a person becomes immune to or resistant to an infectious disease, usually through the injection of a vaccine. These vaccine jibe support the body’s natural defences against illness or infection by boosting immunological function (WHO, 2016) [1,2].
Immunization is one of the most effective and cost-efficient public health interventions, preventing an estimated 3.5-5 million deaths annually from vaccine-preventable diseases and substantially reducing childhood morbidity and mortality worldwide [3]. In India, the Universal Immunization Programme (UIP), supported by initiatives such as Mission Indradhanush, Intensified Mission Indradhanush, and the recently introduced U-WIN digital platform, has substantially strengthened routine immunization services and improved access to childhood vaccines [4-6].
In 2024, 14.3 million children did not receive any vaccination so called the zero-dose children, pointing to a lack of access to immunization and other health services, and an additional 6.2 million are partially vaccinated [2].
The National Family Health Survey-6 (NFHS-6, 2023–24) reported a further improvement in full immunization coverage among children aged 12–23 months at the national level, increasing from 83.8% in NFHS-5 to 87.1%, reflecting the sustained impact of national immunization strategies [7]. However, this national progress conceals considerable interstate and intra-state disparities. Bihar continues to face significant public health challenges characterized by lower maternal educational attainment, socioeconomic inequalities, rural predominance, and disparities in access to quality maternal and child healthcare services, all of which may adversely influence childhood immunization uptake [7,8]. These contextual factors underscore the need for state-specific evidence to support targeted immunization strategies.
Mothers are the principal caregivers and the primary decision-makers regarding childhood vaccination. Their knowledge, attitudes, and practices substantially influence vaccine acceptance, timeliness of vaccination, completion of the recommended immunization schedule, and healthcare-seeking behaviour [10-13/9-12].
Previous studies have consistently identified maternal education, household wealth, antenatal care utilization, counselling by healthcare providers, exposure to mass media, and vaccine confidence as important determinants of childhood immunization [13-16]. Despite improvements in routine immunization coverage, comprehensive evidence regarding maternal KAP and its socio-demographic determinants in Bihar remains limited, particularly in tertiary healthcare settings where mothers from diverse socioeconomic and rural backgrounds seek preventive healthcare services. Identifying these determinants is essential for addressing knowledge gaps, reducing vaccine hesitancy, and developing context-specific interventions to improve equitable immunization coverage.
Therefore, the present study aimed to assess the knowledge, attitude, and practice towards immunization and identify their socio-demographic determinants among mothers of children under five years attending a tertiary care hospital in Bihar.
Material and Methods
This study was a hospital based cross-sectional study conducted at a tertiary care hospital situated in Patna, Bihar, over a six-month period following ethical clearance from the Institutional Ethics Committee. Our study population comprises 410 mothers with children aged up to 5 years who attended the immunization OPD. The study population included mothers of children aged up to five years who had resided in the area for at least six months and provided written informed consent. The response was recorded after taking face to face interview and going through checklist like MCP card, immunization card to ascertain identity and proper recording of socio-demographic data among others. Sample size calculation was based on study conducted by Fadl KH et al.,[1] with taking prevalence of 67%. The sample size calculated by using the Cochrane’s formula [Z2 * p * (1 - p)] / d2 as below where Z = 1.96. Considering the 95% confidence interval and prevalence 67% taken from previous study by Fadl KH et al. and q= 1-P, with an allowable error of 5%. The sample size was coming out to be 340 and with addition of 10% non-response rate, total sample size was adjusted to 374. However, we have taken more sample to increase power of study.
Utilizing a convenience sampling technique, we recruited a total of 410 participants. We interviewed maximum 10 mothers each day with two days in a week. We also rotated the days of data collection every week to reduce the biases by covering all OPD days through this rotation.
Data collection through a pre-tested, semi-structured questionnaire which developed through extensive literature review, texts and related government document, in the English then translated to local language Hindi and back translated to the English so as to check for consistency and validation. It was designed to capture socio-demographic details and Knowledge, attitude and practices regarding immunization. A pilot study conducted to evaluate the tool's feasibility, consistency and flow of questionnaire then it subsequently modified through removal of vague or unclear questions to ensure clarity and ease of understanding for the subjects besides rearranging the question for proper flow and pattern. We manually verified collected data daily at the end of the session for completeness and consistency.
First, each questionnaire was cleaned and checked for completeness. Then the data were entered to EPI info version 7.2.5 computer software. Thereafter the data were exported to SPSS windows version 20 for analysis. Frequency, percentage and mean were run to get descriptive statistics of the data while associations between variables were ascertained using the Chi-square test. Having a p-value less than 0.05 was used to declare the presence of statistically significant association between different variables.
Results
The majority of participating mothers were young adults, with 160 (39.0%) belonging to the 24–29 years age group. Most participants live in urban areas 274 (66.8%) while 147 (35.9%) mothers being graduates however 274 (66.8%) mothers were homemakers. The Hindus makes 336 (82.0%) of population and with regards to socioeconomic classification (the Modified BG Prasad 2025), the largest proportion belonged to the middle socioeconomic class 156 (38.0%), followed by upper-middle 101 (24.6%). Among the children, nearly half 202 (49.3%) were aged 12–24 months and male children comprises 229 (55.9%). More than half of the children were second-born 224 (54.6%), while 267 (65.1%) children were delivered in government health facilities (Table 1).
| Characteristics | Frequency (N) | Percentage (%) |
| Age of mother (in years) | ||
| 18-23 | 91 | 22.2 |
| 24-29 | 160 | 39.0 |
| 30-35 | 113 | 27.6 |
| >35 | 46 | 11.2 |
| Place of residence | ||
| Rural | 136 | 33.2 |
| Urban | 274 | 66.8 |
| Educational status of Mother | ||
| Illiterate | 20 | 4.9 |
| Primary School certificate | 13 | 3.2 |
| Middle school certificate | 7 | 1.7 |
| High school certificate | 32 | 7.8 |
| Intermediate/Diploma | 78 | 19.0 |
| Graduate | 147 | 35.9 |
| Post graduate | 113 | 27.6 |
| Occupation of Mother | ||
| Homemaker | 274 | 66.8 |
| Laborer | 23 | 5.6 |
| Service | 78 | 19.0 |
| Self employed | 35 | 8.5 |
| Religion of mother | ||
| Hindu | 336 | 82.0 |
| Muslim | 68 | 16.6 |
| Others | 6 | 1.5 |
| Socio-economic status (Modified BG Prasad 2025) | ||
| Upper/Class-I | 85 | 20.7 |
| Upper middle/Class-II | 101 | 24.6 |
| Middle/Class-III | 156 | 38.0 |
| Lower middle/Class-IV | 40 | 9.8 |
| Lower/Class-V | 28 | 6.8 |
| Age of child (in months) | ||
| 0-11 | 87 | 21.2 |
| 12-24 | 202 | 49.3 |
| 25-60 | 121 | 29.5 |
| Gender of child | ||
| Male | 229 | 55.9 |
| Female | 181 | 44.1 |
| Parity of child | ||
| 1 | 127 | 31.0 |
| 2 | 224 | 54.6 |
| 3 or more | 59 | 14.4 |
| Place of birth of child | ||
| Gov. health centre | 267 | 65.1 |
| Private Health centre | 123 | 30.0 |
| Others (including home) | 20 | 4.9 |
Knowledge regarding individual vaccines included in the National Immunization Schedule (NIS) varied considerably among mothers. Awareness was highest for the Oral Polio Vaccine 298 (72.7%) and BCG vaccine 294 (71.7%), followed by Hepatitis B vaccine 268 (65.4%) while for Japanese Encephalitis vaccine 204 (49.8%), and for the fractional Inactivated Polio Vaccine (fIPV) was comparatively lower, with only 184 (44.9%) mothers know about it. (Table 2).
| Vaccine | Yes | No |
| Frequency (Percentage) | Frequency (Percentage) | |
| Oral Polio | 298 (72.7) | 112 (27.3) |
| Injectable Polio (fIPV) | 184 (44.9) | 226 (55.1) |
| BCG | 294 (71.7) | 116 (28.3) |
| Pentavalent | 200 (48.8) | 210 (51.2) |
| PCV | 221 (53.9) | 189 (46.1) |
| MR | 195 (47.6) | 215 (52.4) |
| JE | 204 (49.8) | 206 (50.2) |
| Hepatitis B | 268 (65.4) | 142 (34.6) |
| Rotavirus | 222 (54.1) | 188 (45.9) |
| DPT | 241 (58.8) | 169 (41.2) |
| Vitamin A | 246 (60) | 164 (40) |
A total of 287 (70.0%) mothers had heard about the National Immunization Schedule, while 390 (95.1%) reported that their children had received all due vaccinations and 336 (82.0%) possessed an MCP or vaccination card. Awareness regarding adverse events following immunization was reported by 275 (67.1%) participants, however only 178 (43.4%) mothers were aware that a scar develops after BCG vaccination and merely 120 (29.3%) correctly identified the function of booster doses. Overall knowledge regarding childhood immunization was encouraging (Table 3).
| Variable | Yes | No |
| Frequency (Percentage) N (%) | Frequency (Percentage) N (%) | |
| Do you know or heard about NIS | 287 (70) | 123 (30) |
| Does your child get vaccine on first day of birth | 360 (87.8) | 50 (12.2) |
| Does your child receive all due vaccination | 390 (95.1) | 20 (4.9) |
| Know four key messages of vaccination | 236 (57.6) | 174 (42.4) |
| Do you aware that scar is formed after BCG vaccination | 178 (43.4) | 232 (56.6) |
| Know function of booster dose | 120 (29.3) | 290 (70.7) |
| Are you aware of adverse reaction | 275 (67.1) | 135 (32.9) |
| Do you have MCP/vaccination card | 336 (82.0) | 74 (18.0) |
The majority preferred obtaining vaccination services from government health facilities 336 (82.0%). Nearly all participants acknowledged the benefits of vaccination, with 390 (95.1%) agreeing that vaccines are important for children's health. Moreover, 242 (59.0%) strongly supported mandatory childhood vaccination. Similarly, 337 (82.2%) mothers considered childhood immunization to be "very important" for their child's health, while 327 (79.8%) perceived vaccine-preventable diseases as "very serious," reflecting a strong confidence in vaccination. (Table 4)
| Variable | Frequency (N) | Percentage (%) |
| Where do you prefer to go for vaccination | ||
| Government centre | 336 | 82.0 |
| Private centre | 74 | 18.0 |
| Have you searched for vaccination other than NIS | ||
| Yes | 316 | 77.1 |
| No | 94 | 22.9 |
| Do you encourage other mother for child vaccination | ||
| Yes | 393 | 95.9 |
| No | 17 | 4.1 |
| Do you think vaccines are important and beneficial for health | ||
| Yes | 390 | 95.1 |
| No | 20 | 4.9 |
| What is your opinion on mandatory vaccination for all children? | ||
| Strongly support | 242 | 59.0 |
| Support | 152 | 37.1 |
| Neutral | 5 | 1.2 |
| Oppose | 3 | 0.7 |
| Strongly oppose | 8 | 2.0 |
| How important do you believe immunization is for the health of your child? | ||
| Very important | 337 | 82.2 |
| Important | 49 | 12.0 |
| Neutral | 5 | 1.2 |
| Not very Important | 7 | 1.7 |
| Not important at all | 12 | 2.9 |
| How serious do you think is the risk of these diseases prevented by vaccination? | ||
| Very serious | 327 | 79.8 |
| Serious | 51 | 12.4 |
| Neutral | 8 | 2.0 |
| Not very serious | 8 | 2.0 |
| Not serious at all | 16 | 3.9 |
Immunization-related practices were generally satisfactory among study participants. Most mothers reported following the National Immunization Schedule 381 (92.9%) and maintaining their child's vaccination records 384 (93.7%). Additionally, 370 (90.2%) sought appropriate treatment for post-vaccination symptoms, such as fever or swelling, following healthcare workers' advice, and 363 (88.5%) informed healthcare providers about adverse events following immunization. Although, timely vaccination remained a challenge for a substantial proportion of participants. Although 270 (65.8%) mothers reported that they always vaccinated their children according to schedule, 140 (34.2%) acknowledged delays in receiving scheduled vaccinations, indicating opportunities for improving vaccination timeliness despite high overall coverage. (Table-5).
| Variable | Frequency (N) | Percentage (%) |
| Do you follow the NIS | ||
| Yes | 381 | 92.9 |
| No | 29 | 7.1 |
| Do you maintain child vaccination record or history | ||
| Yes | 384 | 93.7 |
| No | 26 | 6.3 |
| Do you always taken vaccination on time | ||
| Yes | 270 | 65.8 |
| No | 140 | 34.2 |
| Have you informed doctor/healthcare worker about side effect (fever, pain, erythema, induration) | ||
| Yes | 363 | 88.5 |
| No | 47 | 11.5 |
| Have you taken treatment for fever, swelling etc as advised by doctor/healthcare worker | ||
| Yes | 370 | 90.2 |
| No | 40 | 9.8 |
No statistically significant association was observed between place of residence and maternal awareness of the National Immunization Schedule, awareness of adverse reactions following immunization p = 0.701), knowledge of booster dose function or receipt of the four key post-immunization messages. Similarly, no significant association was found between residence and adherence to the National Immunization Schedule, maintenance of vaccination records, encouragement of other mothers to vaccinate their children (χ² = 0.36, p = 0.549), or possession of an MCP/vaccination card.
However, significant differences were observed for two
practice-related variables. Complete vaccination coverage was significantly higher among rural mothers 136 (100.0%) than urban mothers 254 (92.7%) (p = 0.003). Similarly, vaccination on the first day of birth was reported more frequently among urban children 264 (96.4%) compared with rural children 96 (70.6%), and this association was highly significant (p < 0.001). These findings indicate that while maternal knowledge regarding immunization was broadly comparable across rural and urban settings, selected immunization practices differed significantly according to place of residence. (Table 6).
| Variable | Rural, (n=136) n (%) | Urban, (n=274) n (%) | Total (N=410) n (%) | χ² (p-value) |
| Awareness of National Immunization Schedule | ||||
| Yes | 100(73.5) | 185 (67.5) | 285 (69.5) | 1.28(0.258) |
| No | 36 (26.5) | 89 (32.5) | 125 (30.5) | |
| Awareness of Adverse Reactions Following Immunization | ||||
| Yes | 89 (65.4) | 186(67.9) | 275 (67.1) | 0.15(0.701) |
| No | 47 (34.6) | 88 (32.1) | 135 (32.9) | |
| Knowledge of Booster Dose Function | ||||
| Yes | 43 (31.6) | 77 (28.1) | 120 (29.3) | 0.39(0.534) |
| No | 93 (68.4) | 197(71.9) | 290 (70.7) | |
| Received Four Key Messages After Immunization | ||||
| Yes | 76 (55.9) | 160(58.4) | 236 (57.6) | 0.14(0.705) |
| No | 60 (44.1) | 114(41.6) | 174 (42.4) | |
| Child Received All Due Vaccinations | ||||
| Yes | 136(100.0) | 254(92.7) | 390 (95.1) | 8.92(0.003) |
| No | 0 (0.0) | 20 (7.3) | 20 (4.9) | |
| Follow National Immunization Program | ||||
| Yes | 122 (89.7) | 259(94.5) | 381 (92.9) | 2.52 (0.112) |
| No | 14 (10.3) | 15 (5.5) | 29 (7.1) | |
| Maintain Immunization Record/Card | ||||
| Yes | 127(93.4) | 257(93.8) | 384 (93.7) | 0.00 (1.000) |
| No | 9 (6.6) | 17 (6.2) | 26 (6.3) | |
| Encourage Other Mothers for Immunization | ||||
| Yes | 132(97.1) | 261(95.3) | 393 (95.9) | 0.36 (0.549) |
| No | 4 (2.9) | 13 (4.7) | 17 (4.1) | |
| Possess MCP/Vaccination Card | ||||
| Yes | 116 (85.3) | 220(80.3) | 336 (82.0) | 1.22 (0.270) |
| No | 20 (14.7) | 54 (19.7) | 74 (18.0) | |
| Child Vaccinated on First Day of Birth | ||||
| Yes | 96 (70.6) | 264(96.4) | 360 (87.8) | 58.40 (<0.001) |
| No | 40 (29.4) | 10 (3.6) | 50 (12.2) |
Discussion
The present study provides an overview of maternal knowledge regarding childhood immunization among mothers attending a tertiary care hospital in Eastern India. Overall, the findings suggest encouraging levels of awareness regarding routine childhood vaccination; however, important gaps remain in vaccine-specific knowledge that may influence timely and complete immunization.
The socio-demographic profile of the participants may partly explain the favourable knowledge observed in this study. Nearly two-fifths of mothers (39.0%) were aged 24–29 years, two-thirds (66.8%) resided in urban areas, and almost two-thirds (63.5%) had graduate or postgraduate education. Maternal education has consistently been identified as one of the strongest predictors of appropriate health-seeking behaviour and childhood immunization uptake, as educated mothers are generally better able to understand vaccination schedules, interpret counselling messages, and utilize preventive health services [1,4,2,17]. Similar demographic characteristics have been reported in studies from Bihar, Karnataka, and other parts of India, where younger and better-educated mothers demonstrated higher awareness regarding childhood vaccination [17-19].
Institutional healthcare utilization was also encouraging in the present study. Nearly two-thirds of children (65.1%) were born in government health facilities, providing an opportunity for timely administration of birth-dose vaccines and counselling regarding subsequent immunization visits. Previous studies have demonstrated that institutional delivery substantially improves the likelihood of initiating and completing childhood immunization because mothers receive counselling immediately after delivery and remain connected with routine health services [4,18,15].
Overall knowledge regarding routine immunization was satisfactory. 70.0% mothers had heard about the National Immunization Schedule, while almost all mothers (95.1%) reported that their children had received all due vaccinations. Likewise, nearly nine out of ten children (87.8%) received vaccination on the first day of birth, reflecting good utilization of birth-dose immunization services. These findings are comparable with recent studies conducted in Bihar and other Indian states, where maternal awareness regarding routine immunization has improved considerably following the implementation of Mission Indradhanush and strengthening of the Universal Immunization Programme [17,18,20].
Knowledge regarding individual vaccines, however, varied considerably. Awareness was highest for long-established vaccines such as Oral Polio Vaccine (72.7%), BCG (71.7%), and Hepatitis B vaccine (65.4%), whereas recognition of relatively newer vaccines including fractional IPV (44.9%), Measles-Rubella (47.6%), Pentavalent vaccine (48.8%), and Japanese Encephalitis vaccine (49.8%) was comparatively lower. Similar trends have been reported in previous studies, suggesting that vaccines introduced more recently into the National Immunization Schedule remain less familiar to caregivers than traditional vaccines that have been promoted for several decades [1,19,21].
Despite encouraging overall awareness, notable deficiencies in technical knowledge were identified. Only about one-third of mothers (29.3%) correctly understood the function of booster doses, while less than half (43.4%) were aware that scar formation following BCG vaccination represents a normal post-vaccination response. These findings indicate that although mothers recognize the importance of immunization, detailed understanding of vaccine schedules and immunological concepts remains limited. Similar observations have been reported from studies conducted in Sudan, Ethiopia, Nigeria, and India, where mothers possessed positive perceptions towards vaccination but had inadequate knowledge regarding booster doses, vaccine schedules, and expected post-vaccination reactions [3,19,22,24].
Awareness regarding adverse events following immunization was relatively good, with approximately two-thirds of mothers (67.1%) reporting knowledge of common vaccine-related adverse reactions. Nevertheless, only slightly more than half (57.6%) recalled the four key post-vaccination messages routinely delivered during immunization sessions. This finding suggests that counselling during vaccination visits may not always be retained or adequately reinforced. Previous studies have similarly highlighted deficiencies in caregiver recall of counselling messages despite satisfactory immunization coverage [20,23,9]. Strengthening interpersonal communication by Auxiliary Nurse Midwives, Accredited Social Health Activists, and other frontline healthcare providers, together with the use of visual educational materials and digital reminder systems, may improve caregiver understanding and reinforce adherence to recommended vaccination practices [4,15,12].
Overall, the findings indicate that maternal knowledge regarding routine childhood immunization is encouraging; however, knowledge remains largely focused on familiar vaccines and general awareness rather than a comprehensive understanding of vaccination schedules and post-immunization care. Future health education strategies should therefore emphasize vaccine-specific counselling, booster dose schedules, recognition of expected adverse events, and reinforcement of key post-vaccination messages. Such targeted interventions may further improve both the completeness and timeliness of childhood immunization and contribute to sustained reductions in vaccine-preventable morbidity and mortality [4,2,12].
Limitations of the study
As this was a cross-sectional study, temporality could not be ascertained. The study may not be generalized to other parts of country because of the difference in socio-demographic and economic conditions and as well as the inclusion of health centre only.
Conclusion
Vaccination completeness is linked with knowledge and practice of mothers and thus there is a need to arrange health education program sessions for mothers of Under five children with main emphasis on importance of vaccination.
Declarations
Acknowledgements
We thank all the participants who participated in this study, and the clinical and nursing staff at the immunization clinic.
Funding/financial support
This research didn’t receive grants from any funding agency in the public, commercial or not-for-profit sectors.
Conflict of interest
The authors declares that they have no conflicts of interest.
Ethical consideration
The ethical approval for study was taken from the Institutional Ethics Committee 1342/IEC/IGIMS/2023 dated 12-12-2023. Informed written consent was taken from parents and confidentiality was ensured along with maintaining privacy at the time of interview.