Delayed vaccination and its predictors among children under 2 years in India: Insights from the national family health survey-4

Worldwide Child Routine Vaccination Hesitancy Rate among Parents of Children Aged 0-6 Years: A Systematic Review and Meta-Analysis of Cross-Sectional Studies

Routine vaccine hesitancy is a major global health challenge observed in over 190 countries worldwide. This meta-analysis aims to determine the worldwide prevalence of routine vaccination hesitancy among parents of children aged 0-6. An extensive search was conducted in four scientific databases: PubMed, Scopus, Web of Science, and the Cochrane Library. Studies were included if they reported hesitancy related to WHO-recommended routine immunizations for children under 7 years of age. A single-arm meta-analysis was performed using the OpenMeta[Analyst] software. An initial search retrieved 5121 articles, of which only 23 publications, involving 29,131 parents, guardians, and caregivers from over 30 countries met the inclusion criteria and quality assessment. The cumulative prevalence of parental vaccine hesitancy was found to be 21.1% (95% CI = 17.5-24.7%, I2 = 98.86%, p < 0.001). When stratifying the prevalence of vaccine hesitancy per WHO region, significant variations were observed, ranging from 13.3% (95% CI = 6.7-19.9%, I2 = 97.72%, p < 0.001) in the Region of the Americas to 27.9% (95% CI = 24.3-31.4%) in the Eastern Mediterranean region. The study findings highlight the need for healthcare providers and governments to develop and improve comprehensive programs with communication strategies to reduce parental vaccine hesitancy.

The effect of the COVID-19 pandemic on routine childhood immunization coverage and timeliness in India: retrospective analysis of the National Family Health Survey of 2019-2021 data

Background

The COVID-19 pandemic has disrupted health systems globally. We estimated the effect of the pandemic on the coverage and timeliness of routine childhood immunization in India through April 2021.

Methods

We used data from India's National Family Health Survey 2019-2021 (NFHS-5), a cross-sectional survey which collected immunization information of under-five children from a nationally representative sample of households between June 2019 and April 2021. We used a mother fixed-effects regression model - accounting for secular trends and confounding factors - to compare COVID-affected children with their COVID-unaffected siblings (n = 59,144). Children who were eligible for a vaccine after January 30, 2020 (date of the first COVID case in India) were considered as the COVID-affected group and those eligible for a vaccine before this date were included in the COVID-unaffected group. Coverage of the following vaccine doses was considered-Bacillus Calmette-Guérin (BCG), hepatitis B birth dose (hepB0), DPT1 (diphtheria, pertussis, and tetanus, first dose), DPT2, DPT3, polio1, polio2, polio3, and measles first dose (MCV1). Indicators of vaccine coverage and vaccine timeliness (defined as receiving a dose within 45 days of minimum eligibility age) were separately examined.

Findings

Immunization coverage was lower in COVID-affected children as compared with unaffected children, ranging from 2% lower for BCG and hepB0 to 9% for DPT3 and 10% for polio3. There was no significant difference in MCV1 coverage. Coverage reduction was greater for vaccines doses given in later age groups. The rate of timely receipt of polio and DPT vaccine doses was 3%-5% lower among COVID-affected children relative to unaffected children. Among population subgroups, COVID-affected male children and those from rural areas experienced the highest reduction in vaccine coverage.

Interpretation

Children in India experienced lower routine immunization coverage and greater delays in immunization during the COVID-19 pandemic.

Funding

The Bill & Melinda Gates Foundation.

Routine childhood vaccination in India from 2005-2006 to 2015-2016: Temporal trends and geographic variation

OBJECTIVE

India has experienced a substantial increase in the coverage of routine childhood vaccines in recent years. However, a large fraction of these vaccines is not delivered in a timely manner, i.e., at the recommended age. Further, substantial disparities exist in both coverage and timeliness across states. We aim to quantify the changes in coverage and timeliness of routine childhood vaccination in India over time, their variation across states, and changes in these variations over time.

METHODS

We used data from two rounds of India's National Family Health Surveys, NFHS-3 (2005-06) and NFHS-4 (2015-16) on bacille Calmette-Guerin vaccine (BCG), three doses of diphtheria, pertussis, and tetanus vaccine (DPT1, DPT2, DPT3), and measles-containing vaccine (MCV). We used the Turnbull estimator to estimate the cumulative distribution function (CDF) of administering each vaccine by a certain age while accounting for two-sided censoring in the survey data. We then used these estimated CDFs to calculate coverage and timeliness at the national and state levels.

FINDINGS

At the national level, both vaccination coverage and timeliness estimates increased from NFHS-3 to NFHS-4 for all vaccines. The increase in timeliness ranging from 27.3% for DPT3 to 74.0% for MCV continued to be lower than coverage, ranging from 75.3% (95% CI 57.7-87.2) for DPT3 to 74.0% (95% CI 42.2-33.0) for MCV, for all vaccines. Cross-state variation in timeliness was greater than the variation in coverage. Variation in both timeliness and coverage reduced from NFHS-3 to NFHS-4. However, this reduction was greater for timeliness than for coverage.

CONCLUSIONS

A large fraction of the children in India receive vaccines later than the recommended age thereby keeping them exposed to vaccine-preventable diseases. Interventions that specifically focus on improving the timely delivery of vaccines are needed to improve the overall effectiveness of the routine immunization program.

Timeliness of routine childhood vaccination in 103 low-and middle-income countries, 1978-2021: A scoping review to map measurement and methodological gaps

Empiric studies exploring the timeliness of routine vaccination in low-and middle-income countries (LMICs) have gained momentum in the last decade. Nevertheless, there is emerging evidence suggesting that these studies have key measurement and methodological gaps that limit their comparability and utility. Hence, there is a need to identify, and document these gaps which could inform the design, conduct, and reporting of future research on the timeliness of vaccination. We synthesised the literature to determine the methodological and measurement gaps in the assessment of vaccination timeliness in LMICs. We searched five electronic databases for peer-reviewed articles in English and French that evaluated vaccination timeliness in LMICs, and were published between 01 January 1978, and 01 July 2021. Two reviewers independently screened titles and abstracts and reviewed full texts of relevant articles, following the guidance framework for scoping reviews by the Joanna Briggs Institute. From the 4263 titles identified, we included 224 articles from 103 countries. China (40), India (27), and Kenya (23) had the highest number of publications respectively. Of the three domains of timeliness, the most studied domain was 'delayed vaccination' [99.5% (223/224)], followed by 'early vaccination' [21.9% (49/224)], and 'untimely interval vaccination' [9% (20/224)]. Definitions for early (seven different definitions), untimely interval (four different definitions), and delayed vaccination (19 different definitions) varied across the studies. Most studies [72.3% (166/224)] operationalised vaccination timeliness as a categorical variable, compared to only 9.8% (22/224) of studies that operationalised timeliness as continuous variables. A large proportion of studies [47.8% (107/224)] excluded the data of children with no written vaccination records irrespective of caregivers' recall of their vaccination status. Our findings show that studies on vaccination timeliness in LMICs has measurement and methodological gaps. We recommend the development and implement of guidelines for measuring and reporting vaccination timeliness to bridge these gaps.

Timeliness of routine childhood vaccinations in Indonesian infants in the first year of life

BACKGROUND

Vaccines have proven to be one of the most effective strategies to control infectious diseases and contributed to childhood survival. While high vaccine coverages provide individual's and herd immunity, age-appropriate vaccination or vaccine timeliness is important for maximum vaccine's protection, but often not evaluated. We aimed to describe the timeliness of childhood vaccination for Indonesian infants and identify risk factors associated with delayed vaccination.

METHODS

This study was a sub-study of the Indonesian Pneumonia and Vitamin D status (IPAD) study, a community-based cohort study to investigate pneumonia incidence in two districts in Yogyakarta province, Indonesia. Socio-demographic data were obtained from structured interviews and vaccine status was obtained from maternal and child health records. Timely vaccination was defined if the vaccine was received between four days or less before and within 28 days after the recommended age of vaccination.

RESULTS

359 (85%) out of 422 IPAD participants and their immunisation records were included. Between December 2015 and December 2017, vaccination coverage was high and ranged from 96.1% (Measles) to 100% (DTP-HepB-Hib 1). However, two thirds (67%, 242/359) of all participants had received either early or late vaccines, with dose 2 IPV (40%, 143/356), dose 3 IPV (56%, 196/349) and dose 3 DTP-HepB-Hib (29%, 103/354) most delayed, and only 1% received early doses. The main risk factors for untimely vaccination were if the infant was born in a private practice versus in a public health facility (AOR 1.90; 95% CI: 1.18-3.07) and rural residence (AOR 1.84; 95% CI: 1.15-2.94).

CONCLUSIONS

Despite high vaccine coverage for Indonesian infants (>95%), two thirds (67%) of infants had untimely vaccinations, with dose 3 IPV (56%) the most delayed. Future strategies should focus on coordination between government, health care providers, and carers to ensure timely access and vaccination of infants to ensure adherence to vaccination schedules.

Are children on track with their routine immunization schedule in a fragile and protracted conflict state of South Sudan? A community-based cross-sectional study

Objectives

The objective of this study was to assess if children aged 0–23 months in a conflict-affected state of South Sudan were on track with their immunization schedule and to identify predisposing factors that affected this study population from being on track with their routine immunization schedule.

Design

Community-based cross-sectional study using a semi-structured questionnaire. The binary outcome of interest was defined as being on or off track with routine vaccination schedule. Multivariable logistic regression was used to analyze for the association between the predisposing factors surveyed and being off track with one’s routine immunization schedule.

Setting

Rural communities in four counties (Rumbek Center, Rumbek North, Rumbek East and Wulu) of the Western Lakes state in South Sudan during January 10, 2020 to June 10, 2020.

Participants

We surveyed 428 children aged 0–23 months and their mothers/caregivers who lived in either of the four counties in the Western Lakes State. Participants were selected using random ballot sampling.

Results

More than three-quarters of the children surveyed (75.5%) were off track with their vaccination schedule. Children with an immunization card had 71% reduced odds of being off track with their immunization (AOR = 0.29; 95% CI 0.10–0.83, p-value = 0.021) compared to children without immunization cards. Children who reside near health facilities and do not require transportation to facilities had 87% reduced odds of being off track with their immunization compared to those who lived far and required transport to facilities. Giving an adequate immunization notice before conducting immunization outreach visits to communities was also associated with reduced odds (AOR = 0.27; 95% CI 0.09–0.78. p-value = 0.016) of children being off track with their immunization.

Conclusion

This study revealed that most children were off track with their vaccination schedule in South Sudan, which is not only influenced by maternal characteristics but mainly by community- and state-level immunization service delivery mechanisms. Policies and interventions to improve child immunization uptake should prioritize these contextual characteristics.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-022-03213-5.

Vaccination timeliness and associated factors among children aged 12-23 months in Debre Libanos district of North Shewa Zone, Oromia Regional State, Ethiopia

BACKGROUND

Globally, vaccination is one of the most cost-effective interventions in promoting child survival, preventing 2-3 million child deaths annually from vaccine-preventable diseases (VPDs). In Ethiopia, timely vaccination is stated as key to the prevention of unnecessary childhood mortality from measles, pneumonia, diarrheal diseases, and other VPDs. However, Ethiopia ranked fifth among the ten countries with the most unprotected children. Furthermore, previous vaccine timeliness studies produced widely disparate results. As a result, it was suggested that more research be conducted to investigate the potential factors behind the high proportion of untimely vaccination. Therefore, this study was intended to explore the association between different factors and the proportion of vaccination timeliness administered under the Expanded Program on Immunization in Debre Libanos district, Ethiopia.

METHODS

A community-based cross-sectional study design was employed from 1 May to 30 May 2021 among children aged 12 to 23 months with their mother/caregiver, who had started vaccination and had vaccination cards in the Debre Libanos. Simple random sampling techniques and pretested semi-structured questionnaires were used for data collection. At last, a multivariable logistic regression was used to identify factors associated with the vaccination timeliness.

RESULT

In this study, 413 children aged 12 to 23 months were interviewed with their mother/caregiver. Overall, 33.7% [95% CI (29.1-38.3)] of children received their vaccines timely. Having a female child [AOR: 2.9, 95% CI: 1.58-5.35], mother/caregiver attending primary [AOR: 6.33, 95% CI: 2.66-15.06] and secondary/above education [AOR: 5.61, 95% CI: 2.41-13.04], sufficient vaccination knowledge [AOR: 3.46, 95% CI: 1.87-6.38], mother/caregiver with least hesitant [AOR: 3.35, 95% CI: 1.51-7.41] and middle hesitant [AOR: 1.89, 95% CI: 1.05-3.58], utilization of ANC [AOR: 2.89, 95% CI: 1.32-6.33], and giving birth at health facility [AOR: 4.32, 95% CI: 1.95-9.59] were the factors independently associated with vaccination timeliness.

CONCLUSION

In comparison to Ethiopia's existing vaccination coverage, the proportion of children immunized at the recommended time interval is low in the study district. Policymakers should prioritize vaccine timeliness and integrate it into childhood vaccination strategies.

Age-appropriate vaccination coverage and its determinants in children aged 12-36 months in Nepal: a national and subnational assessment

Background

Vaccination is one of the effective ways to develop immunity against potential life-threatening diseases in children in early age. This study is focused on analysing the age-appropriate vaccination coverage at national and subnational levels and identify the factors associated with age-appropriate coverage in Nepal.

Methods

460 children aged 12–36 months were included in the study. The data was obtained from Nepal Demographic and Health Survey (NDHS) 2016–17. Age-appropriate coverage of Bacillus Calmette-Guerin vaccine (BCG), oral polio vaccine (OPV) doses 1–3, pentavalent vaccine (PE) doses 1–3, and first dose of measles, mumps, and rubella vaccine (MMR) were estimated using Kaplan Meier method. Multilevel logistic regression with random intercept was used to identify the factors associated with age-appropriate vaccination.

Results

The crude coverage of the vaccines included in the study ranged from 91.5% (95% CI, 88.5–93.7) for PE3 to 97.8% (95.8–98.7) for BCG. Although the crude coverage of all the vaccines was above 90%, the age-appropriate coverage was significantly low, ranging from 41.5% (36.5–46.6) for PE3 to 73.9% (69.2–78.1) for PE1. Furthermore, high disparity in timely vaccination coverage was observed at regional level. Compared to the age-appropriate vaccination coverage in other provinces, Province 2 had the lowest coverage of all, followed by that in Province 6. The timeliness of vaccination was significantly associated with subnational regions i.e., provinces and the season of childbirth.

Conclusion

Although the immunization program in Nepal has achieved the target of 90% crude coverage of all the childhood vaccines, the age-appropriate coverage is significantly low which undermines the effectiveness of the vaccines administered. Thus, along with crude coverage, timeliness of the vaccines administered should be taken into consideration and thoroughly monitored at national and subnational levels. Provincial government should formulate tailored strategies to ensure the timely administration of the childhood vaccines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11841-2.

Improving vaccination coverage and timeliness through periodic intensification of routine immunization: evidence from Mission Indradhanush

Only an estimated 62% of Indian children under the age of 2 years are fully immunized. We examined the association between India's Mission Indradhanush (MI)-a periodic intensification of the routine immunization program-which was implemented in phases across districts between March 2015 and July 2017, and routine vaccination coverage and timeliness among children. We used data from a 2015 to 2016 national survey of children (n = 29,532) and employed difference-in-difference regressions to examine binary indicators of receipt of 11 vaccines and whether vaccines were received at recommended ages. The full immunization rate was 27% higher among children under 2 years old residing in MI phase 1 and 2 districts (intervention group) as compared with those residing elsewhere (control group). The rate of receiving all vaccines at recommended ages was 8% higher in the intervention group. Receiving doses of oral polio vaccine (OPV) birth dose, OPV dose 1 (OPV1), OPV2, OPV3, bacillus Calmette-Guérin, and hepatitis B birth dose vaccines were 9%, 9%, 11%, 16%, 5%, and 19% higher in the intervention group than the control group, respectively. More research is required on the cost-effectiveness of investing in MI-type programs as compared with routine immunization.

COVID-19 related immunization disruptions in Rajasthan, India: A retrospective observational study

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Disruptions during the COVID-19 lockdown caused children to miss immunizations.

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Government catch-up efforts substantially reversed these effects.

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Yet, children that were due vaccinations during the lockdown remained 10–15% less likely to be immunized 4–5 months later.

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Catch-up was more likely to be incomplete among children of low socioeconomic status.

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Ensuring all children are fully immunized requires careful tracking and disaggregated data.

Introduction

Governments around the world suspended immunization outreach to control COVID-19 spread. Many have since resumed services with an emphasis on catch-up vaccinations. This paper evaluated immunization disruptions during India’s March-May 2020 lockdown and the extent to which subsequent catch-up efforts reversed them in Rajasthan, India.

Methods

In this retrospective observational study, we conducted phone surveys to collect immunization details for 2,144 children that turned one year old between January and October 2020. We used logistic regressions to compare differences in immunization timeliness and completed first-year immunization status among children that were due immunizations just before (unexposed), during (heavily exposed), and after (post-exposure) the lockdown.

Results

Relative to unexposed children, heavily exposed children were significantly less likely to be immunized at or before 9 months (OR 0.550; 95% CI 0.367–0.824; p = 0.004), but more likely to be immunized at 10–12 months (OR 1.761; 95% CI 1.196–2.591; p = 0.004). They were also less likely to have completed their key first-year immunizations (OR 0.624; 95% CI 0.478–0.816; p = 0.001) by the time of survey. In contrast, post-exposure children showed no difference in timeliness or completed first-year immunizations relative to unexposed children, despite their younger age. First-year immunization coverage among heavily exposed children decreased by 6.9 pp to 10.4 pp (9.7% to 14.0%). Declines in immunization coverage were larger among children in households that were poorer, less educated, lower caste, and residing in COVID red zones, although subgroup comparisons were not statistically significant.

Conclusion

Disruptions to immunization services resulted in children missing immunization during the lockdown, but catch-up efforts after it was eased ensured many children were reached at later ages. Nevertheless, catch-up was incomplete and children due their immunizations during the lockdown remained less likely to be fully immunized 4–5 months after it lifted, even as younger cohorts due immunizations in June or later returned to pre-lockdown schedules.

Timeliness, completeness, and timeliness-and-completeness of serial routine vaccinations among rural children in Southwest China: A multi-stage stratified cluster sampling survey

INTRODUCTION

Vaccination coverage is widely used as metric of vaccination programme performance. However, VPDs outbreaks were reported in areas with high vaccination coverage. Timeliness and completeness have been considered more important assessment indicators of routine vaccination than overall vaccination coverage, but little is known in rural China. This study aimed to assess the timeliness and completeness of serial routine vaccinations among children in rural Southwest China.

METHODS

A multi-stage stratified cluster survey was conducted among 1062 children aged 18-48 months in rural Guangxi. Vaccination status was obtained from child's vaccination certificate. We calculated timely vaccination coverage, complete vaccination coverage, timely-and-complete vaccination coverage and 95% CI for routine vaccination through weighted estimation analysis. Weighted Kaplan-Meier analyses were applied to estimate the median delay periods for each dose of serial routine vaccines, including one-dose BCG, three-dose HepB, three-dose OPV, four-dose DTP, two-dose MCV, two-dose JEV and two-dose MPV-A. Complete coverage, and timely-and-complete coverage for combined 5-vaccine series were calculated.

RESULTS

For each dose of routine vaccines, overall vaccination coverages were over 90%, but timely vaccination coverage ranged from the lowest of 44.4% for JEV1 to the highest of 92.5% for MPV-A1. For multi-dose routine vaccines, complete vaccination coverages varied from the lowest of 92.9% for MCV to the highest of 100% for HepB, and timely-and-complete vaccination coverages were lower than 80%, ranging from the lowest of 30% for JEV to the highest of 77.2% for MPV-A. For combined 5-vaccine series, complete coverage was 77%, while timely-and-complete coverage was 12.1%. MPV-A1 had the longest median delay of 176 days, but BCG and HepB1 had the shortest of 1 day.

CONCLUSIONS

The overall coverages of serial routine vaccinations were high, but the timeliness and completeness were poor. Relevant agencies of vaccination service should address timeliness-and-completeness into the assessment indicators of routine vaccination service quality.

Determinants of childhood vaccination in Nagaland, India: a cross-sectional study with multilevel modelling

OBJECTIVES

Childhood vaccination coverage in Nagaland has lagged almost all states in India for more than two decades. This study aims to find drivers and barriers of childhood vaccination in Nagaland from the perspective of demand, supply and local health governance.

DESIGN

A cross-sectional study was designed using a survey conducted by the Directorate of Health and Family in 2015.

SETTING

Households, community-based health centres and health committees were surveyed.

PARTICIPANTS

285 children aged under 2 years with vaccination cards and data on households, health centres and health committees were included.

OUTCOMES

Variables indicating whether a child received each of bacillus calmette-guérin (BCG), diphtheria-tetanus-pertussis (DTP3), oral polio (OPV3) and measles vaccination and all of them were outcome variables. Associated factors were identified using multilevel logistic regressions.

RESULTS

Antenatal care at least three times was significantly associated with BCG, DTP3, OPV3 and full vaccination with adjusted ORs ranging from 2.4 (95% CI 1.1 to 5.1) to 3.3 (1.1 to 9.9). The availability of bus to health centre was slightly significant for BCG and OPV3 with the adjusted ORs of 2.0 (0.9 to 4.5) and 2.1 (0.9 to 4.8), respectively. Health committees' budget provision to health centres was significant for OPV3 and full vaccination with the respective adjusted ORs of 15.7 (1.0 to 234.1) and 15.9 (1.2 to 214.7), the wide 95% CIs of which were driven by a small sample size. Health committees' review of expenditure of health centres was significant for measles and full vaccination with the adjusted ORs of 4.0 (1.4 to 11.4) and 5.2 (1.4 to 19.4), respectively.

CONCLUSION

This study suggests that enhancing the utilisation of antenatal care and providing reliable transportation between villages and health centres are required to improve childhood vaccination coverage. Also, the significant association of budget administration of health committees suggests that supporting local health committees for effective financial management is important.

Timeliness of childhood vaccinations in the Philippines

Timeliness of vaccinations is rarely part of monitoring in a routine immunization program. We reviewed infant immunization and conducted caregiver interviews in three regions in the Philippines from January to October 2016. We randomly selected thirty public health centers, one for each region. We defined timeliness of the receipt of antigen as within 4 weeks after the recommended age at vaccination. We assessed a total of 986 infants for timeliness of vaccination. The median age of receipt of vaccine was at 2.7 weeks (BCG), 10.1 weeks (Penta 1), and 21.7 weeks (Penta 3) compared to the recommended 0, 6, and 14 weeks of age, respectively. We found timely receipt only in 74.4% for BCG, 70.3% for Penta 1, and 39.1% for Penta 3 recipients. Thus, alongside declining immunization coverage, the infants in the Philippines had substantial delays in vaccine receipt.

Vaccination in preterm and low birth weight infants in India

In India, the high neonatal and infant mortality rate is due in part to an increasing number of preterm and low birth weight (LBW) infants. Given the immaturity of immune system, these infants are at an increased risk of hospitalization and mortality from vaccine-preventable diseases (VPDs). In this narrative review, we screened the scientific literature for data on the risk of VPDs, vaccination delay and factors related to it in Indian preterm and LBW infants. Although routine childhood vaccinations are recommended regardless of gestational age or birth weight, vaccination is often delayed. It exposes these infants to a higher risk of infections, their associated complications, and death. After-birth complications, lack of awareness of recommendations, vaccine efficacy and effectiveness and concerns related to safety are some of the common barriers to vaccination. Awareness campaigns might help substantiate the need for (and value of) vaccination in preterm and LBW infants.

What is the context?

In India, the high neonatal mortality rate is due in part to an increasing number of pretern and low birth weight intants.

Affected infants have a poorly developed inmune system and are more susceptible to contracting vaccine-preventable diseases.

The Indian Academy of Pediatrics recommends vaccination according to the same schedule used for full term infants, following chronological (not gestational) age.

Delays in vaccinations increase the risk of preventable infections.

What is new?

Our review of the scientific literature shows that, in India:

infections have more serious conseuences in preterm and low birth weight infants

delays to vaccinate affected infants are common, mostly due to safety and effectiveness concerns from parents and healthcare pracitionrs.

What is the impact?

Improving mternal nutritional status and immunization, and perinatal care could help reduce the number of preterm and low birth weight infants.

Combining maternal immunization with vaccination of affected infants can confer safe and effective protection.

Awareness campaigns for parents and healthcare practitioners could address the issue of vaccination delay in pretern and low birth weight infants in India.

Timeliness of immunisation with the pentavalent vaccine at different levels of the health care system in the Lao People's Democratic Republic: A cross-sectional study

Background

The timely administration of vaccines is considered to be important for both individual and herd immunity. In this study, we investigated the timeliness of the diphtheria-tetanus-whole cell pertussis-hepatitis B-Haemophilus influenzae type b (pentavalent) vaccine, scheduled at 6, 10 and 14 weeks of age in the Lao People’s Democratic Republic. We also investigated factors associated with delayed immunization.

Methods

1162 children aged 8–28 months who had received the full course of the pentavalent vaccine at different levels of the health care system were enrolled. Vaccination dates documented in hospital records and/or immunisation cards were recorded. Age at vaccination and time intervals between doses were calculated. Predictors for timely completion with the pentavalent vaccine at 24 weeks were assessed by bivariate and multivariable analyses.

Results

Several discrepancies in dates between vaccination documents were observed. In general, vaccination with the pentavalent vaccine was found to be delayed, especially in health care settings below the provincial hospital level. Compared to the central hospital level, less participants who were vaccinated at the district/health center level received the third dose by 16 (48% at the central hospital level vs. 7.1% at the district and 12.4% at the health center level) and 24 weeks of age (94.4% at the central hospital level vs 64.6% at the district-outreach and 57.4% at the health center level) respectively. In logistic regression analyses, lower education level of the mother as well as vaccination by outreach service, were independently associated with delayed completion of vaccination.

Conclusion

We observed a general delay of vaccination, especially at lower ranked facilities, which correlated with indicators of poor access to health services. This highlights the need for further improving health equity in rural areas. Age-appropriate vaccination should become a quality indicator for the national immunization programme. In addition, we recommend further training of the health care staff regarding the importance of reliable documentation of dates.