Completeness and timeliness of vaccination and determinants for low and late uptake among young children in eastern China

Spatial pattern and associated factors of timely vaccination in Ethiopia using EDHS-2016 data: A multilevel and spatial analysis

BACKGROUND

Age-appropriate vaccination or vaccine timeliness is the administering of vaccines on the specified schedule of immunization. One of the qualities of the immunization program is an age-appropriate vaccine, it has become an ignored indicator of program performance. Even though age-appropriate vaccination is critical for child health, there are no national-level studies to generate conclusive and tangible evidence about the determination of timely vaccination in Ethiopia.

OBJECTIVE

To assess the spatial pattern and associated factors of timely vaccination in Ethiopia using EDHS-2016 data: A multilevel and spatial analysis.

METHOD

Community based cross-sectional study design was employed from 18 January to 27 June 2016. To select the participants, two-stage cluster sampling was employedin the Ethiopian Demographic Health Survey 2016 data. Permission was obtained via online request by explaining the aim of this particular study from DHS international. A statistical package for social science-21 software was used for data cleaning, recoding, and analysis. Arc GIS 10.3 software was used to show the spatial variation of age-appropriate vaccination practices. A generalized linear mixed-effect model was used. For all models, intra-class correlation, a proportional change in variance, the log-likelihood test, and the Akaike information criterion were calculated. The best model was selected by the lowest value Akaike information criterion. Variables with a p-value less than 0.05 and a 95% confidence level were considered for the statistically significant association.

RESULT

The spatial distribution of age-appropriate vaccination practice in Ethiopia was non-randomly distributed with the global Moran's I value of 0.22 (p-value <0.001). The prevalence of age-appropriate vaccination practice in Ethiopia was 33.8%. Women who receive ≥ 2 TT vaccines (AOR = 1.48; 1.22, 1.79), women who lived in rural residences (AOR = 0.77; 0.62, 0.96), gave birth at a health facility (AOR = 1.2; 1.12, 1.37), ANC follow up (AOR = 174; 1.45, 2.1), richest (AOR = 1.65; 1.15, 2.37), richer (AOR = 1.72; 1.3, 2.22), middle-level income (AOR = 1.65; 1.16, 2.36), poorer (AOR = 1.47; 1.11, 1.96) were the factors of age-appropriate vaccination practice.

CONCLUSION

The spatial distribution of age-appropriate vaccination practice in Ethiopia was non-randomly distributed across the regions. Age-appropriate vaccination practice was low in Ethiopia. Wealth index, usual caretaker of the child, ANC utilization, history of TT vaccination, place of delivery, and residence were associated with age-appropriate vaccination practice.

Trends in Vaccine Completeness in Children Aged 0-23 Months in Cape Town, South Africa

BACKGROUND

We have previously determined that the occurrence of missed vaccination opportunities in children in Cape Town, South Africa, is shaped by both individual and contextual factors. These factors present valuable openings for enhancing quality and implementing broader strategies to enhance the delivery of routine Immunisation services.

METHODS

Here, we are further reporting regional-level data on the coverage and factors influencing vaccination completion within a similar study population, based on extensive data analysis from the 2016 South African Demographic and Health Survey.

RESULTS AND DISCUSSION

The study reveals commendable vaccination coverage for most vaccines within recommended schedules, with high rates of initial vaccinations at birth and during the primary vaccination schedule. However, there are notable areas for improvement, particularly in ensuring complete coverage for the second measles vaccine and the 18-month vaccine. Socio-demographic factors also play a role, with maternal education and caregiver awareness campaigns showing the potential to positively influence vaccination completeness. This study emphasises the importance of timely vaccinations during the early months of life and underscores the need for interventions to maintain coverage as children age. Specific sub-districts, such as Tygerberg, may require targeted efforts to enhance vaccination completeness. Additionally, assessing caregiver knowledge about child vaccination is deemed vital, as it can impact vaccination decisions and adherence.

CONCLUSIONS

The findings provide valuable insights for public health interventions in Cape Town, aimed at reducing the burden of vaccine-preventable diseases and ensuring the health of the region's youngest population.

An assessment of the effectiveness of an electronic wristband in improving routine immunization timeliness and reducing drop-out

BACKGROUND

To assess the effectiveness of a wristband for immunization alert (WIA) as a reminder device to caregivers to improve immunization timeliness and reduce drop-outs.

METHODS

Eight health facilities, selected from two local government areas in Kano state, Northwestern Nigeria, were clustered in a two-arm study involving an intervention group and a control group. Only the caregivers (757) from the intervention group received WIA as an immunization reminder device. Immunization timeliness data were then collected from the control and intervention groups for the period of intervention and analyzed using Microsoft Excel and IBM SPSS version 21.

RESULTS

A cohort analysis of caregivers who received WIA at their second visit showed an increase in immunization timeliness from 10% at the second visit to 86% at the third visit and maintained at 66% for the fifth visit. A difference-in-difference analysis of the effect of WIA on immunization timeliness from baseline to end-line in the control and intervention groups showed a positive 30% increase in immunization timeliness associated with the introduction of WIA.

INTERPRETATION

Given that immunization timeliness and drop-outs are reported issues of concern in Northwestern Nigeria, the use of the WIA device is a recommended intervention.

Immunization coverage, knowledge, satisfaction, and associated factors of non-National Immunization Program vaccines among migrant and left-behind families in China: evidence from Zhejiang and Henan provinces

BACKGROUND

Migrant and left-behind families are vulnerable in health services utilization, but little is known about their disparities in immunization of non-National Immunization Program (NIP) vaccines. This study aims to evaluate the immunization coverage, knowledge, satisfaction, and associated factors of non-NIP vaccines among local and migrant families in the urban areas and non-left-behind and left-behind families in the rural areas of China.

METHODS

A cross-sectional survey was conducted in urban areas of Zhejiang and rural areas of Henan in China. A total of 1648 caregivers of children aged 1-6 years were interviewed face-to-face by a pre-designed online questionnaire, and their families were grouped into four types: local urban, migrant, non-left-behind, and left-behind. Non-NIP vaccines included Hemophilus influenza b (Hib) vaccine, varicella vaccine, rotavirus vaccine, enterovirus 71 vaccine (EV71) and 13-valent pneumonia vaccine (PCV13). Log-binomial regression models were used to calculate prevalence ratios (PRs) and 95% confidence intervals (CIs) for the difference on immunization coverage of children, and knowledge and satisfaction of caregivers among families. The network models were conducted to explore the interplay of immunization coverage, knowledge, and satisfaction. Logistic regression models with odds ratios (ORs) and 95% CIs were used to estimate the associated factors of non-NIP vaccination.

RESULTS

The immunization coverage of all non-NIP vaccines and knowledge of all items of local urban families was the highest, followed by migrant, non-left-behind and left-behind families. Compared with local urban children, the PRs (95% CIs) for getting all vaccinated were 0.65 (0.52-0.81), 0.29 (0.22-0.37) and 0.14 (0.09-0.21) among migrant children, non-left-behind children and left-behind children, respectively. The coverage-knowledge-satisfaction network model showed the core node was the satisfaction of vaccination schedule. Non-NIP vaccination was associated with characteristics of both children and caregivers, including age of children (> 2 years-OR: 1.69, 95% CI: 1.07-2.68 for local urban children; 2.67, 1.39-5.13 for migrant children; 3.09, 1.23-7.76 for non-left-behind children); and below caregivers' characteristics: family role (parents: 0.37, 0.14-0.99 for non-left-behind children), age (≤ 35 years: 7.27, 1.39-37.94 for non-left-behind children), sex (female: 0.49, 0.30-0.81 for local urban children; 0.31, 0.15-0.62 for non-left-behind children), physical health (more than average: 1.58, 1.07-2.35 for local urban children) and non-NIP vaccines knowledge (good: 0.45, 0.30-0.68 for local urban children; 7.54, 2.64-21.50 for left-behind children).

CONCLUSIONS

There were immunization disparities in non-NIP vaccines among migrant and left-behind families compared with their local counterparts. Non-NIP vaccination promotion strategies, including education on caregivers, and optimization of the immunization information system, should be delivered particularly among left-behind and migrant families.

Delays in the vaccination of infants between 2 and 18 months of age: associated factors in Chile

INTRODUCTION

Infant vaccination has significantly reduced the morbidity and mortality of transmittable diseases worldwide. Its coverage is high (85%); however, partial or suboptimal vaccination has been an important public health problem. This study aimed (1) to design and explore the psychometric features of a questionnaire to determine the reasons for this partial or suboptimal vaccination; and 2) to determine the factors associated with delaying Diphtheria, Tetanus, Poliomyelitis (DTaP) vaccination.

MATERIAL AND METHODS

This study contained two parts. In Part One, a questionnaire was created by the research team and then validated by a committee of experts in the field and a group of parents. It included the following contents: sociodemographic variables, features of the vaccination services, history of vaccination, and attitudes and perceptions about vaccination. Part Two was a cross-sectional study, recruiting private and public healthcare centers to explore the psychometrics features of the instrument, performing exploratory factor analysis, and determining the associated factors with DTaP vaccination delay throughout multivariable regression models.

RESULTS

Initially, six experts validated the questionnaire. For instance, on a scale of 1 to 5, the general evaluation of the questionnaire was ≥ 4 for all the experts. Additionally, five experts considered that most of the questions were easy to understand, and all thought the questionnaire had a clear and logical organization. The resulting questionnaire included the "Trust and positive attitude towards vaccination" scale, which had a good structure of items and internal consistency (α = 0.7918). Six healthcare centers were recruited in the second part of the study, and 715 people answered the questionnaire. Not being the mother who brings the child to the health center, having more than one child, and having a history of previous vaccination delays increased the risk of delaying vaccination. Attending the healthcare center for a reason other than only vaccination, obtaining information about vaccines from the Internet, and having higher trust and positive attitudes to vaccination reduced the risk of delay.

CONCLUSIONS

First study during the pandemic to explore the role of different factors on the risk of DTaP vaccination delay in Latin America. The findings highlighted the importance of trust in the vaccination system. The instrument presented in this article may help the scientific community evaluate future interventions to increase trust and positive attitudes toward the vaccination process.

Predictors of timeliness of vaccination among children of age 12-23 months in Boricha district, Sidama region Ethiopia, in 2019

BACKGROUND

Traditional measurement of vaccine coverage can mask the magnitude of timely uptake of vaccine. Hence, the optimal measurement of timeliness is unclear due to variations in vaccine schedule among countries in the world. In Ethiopia, Oral Polio Virus (OPV), Pentavalent, Tetanus, H. influenza type B, Hepatitis B, and Pneumonia-Conjugate Vaccine (PCV) are basic vaccines which are taken at birth, six weeks, ten weeks, and fourteen weeks respectively. Despite its importance, information is scarce about on-time vaccination in the study area. Therefore, this study aimed to assess prevalence and factors associated with on-time vaccination among children of age 12-23 months in Boricha district, Sidama Ethiopia, in 2019.

METHODS

A community based survey was conducted in Boricha district, Sidama region Ethiopia from January 1-30 in 2019. Study participants were selected using stratified multistage sampling technique. Kebeles were stratified based on residence. First, Kebeles were selected using random sampling. Then, systematic random sampling was employed to reach each household. Data were collected using structured and interviewer administered questionnaire. Logistic regression analysis was employed to identify factors associated with timely vaccination. Then, independent variables with p-value < 0.25 in COR were fitted further into multivariate logistic regression analysis model to control the possible cofounders. AOR with 95% CI and p-value < 0.05 was computed and reported as the level of statistical significance.

RESULTS

From a total of 614 study participants, only 609 study participants have responded to questions completely making a response rate of 99.2%. Prevalence of timeliness of vaccination was 26.8% (95% CI: 25, 28) in this study. Factors like children of women with formal education (AOR = 5.3, 95%CI,2.7, 10.4), absence of antenatal care visit (AOR = 4.2,95%CI, 1.8,9.8), home delivery (AOR = 6.2,95%CI,4.0,9.3), lack of postnatal care (AOR = 3.7,95%CI,1.1,13.3), and lack of information about when vaccines completion date (AOR = 2.0, 95% CI,1.13,3.8) were factors influences timely vaccination among children of age 12-23 months.

CONCLUSION

Prevalence of on-time vaccination among children of age 12-23 months is lower than national threshold. Therefore, sustained health education on vaccination schedule and reminder strategies should be designed and implemented. Furthermore, maternal and child health care services should be enhanced and coordinated to improve on-time uptake of vaccine.

Prevalence and factors associated with incomplete immunization among children aged 12 to 35 months in Eswatini: analysis of the Eswatini multiple indicator cluster survey

Introduction

incomplete childhood immunization is a significant public health challenge as children continue to succumb to vaccine-preventable diseases in most developing countries. Studies on childhood immunization conducted in Eswatini are sparse. Therefore, the present study assessed the prevalence of incomplete childhood immunization in Eswatini and further explored associated factors among children aged 12 to 35 months.

Methods

using data from Eswatini multiple indicator cluster survey 5 (EMICS5), a cross-sectional analysis with 978 children aged 12 to 35 months was conducted. This is the latest available data in the public domain. The survey was conducted from July 2014 to October 2014. The primary outcome variable was incomplete immunization. Univariate and multivariate logistic regressions were used to examine the association between selected variables and incomplete immunization.

Results

the mean age of the children was 23.45±6.92 months, 50.2% were boys, and 74.1% lived in rural areas. The prevalence of incomplete immunization was 31.5%. Increased child´s age, being a girl, increased caregiver´s age, and increased number of children under-five years in the household and residing in the Manzini or Hhohho region were significantly associated with incomplete immunization.

Conclusion

the EMICS 5 revealed a high prevalence of incomplete immunization in Eswatini. Health promotion activities such as empowering women and caregivers of children through health education about child health should be emphasized. Where feasible, outreach services and door-to-door immunization should be strengthened to improve immunization coverage in the country and cover dropouts.

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.

Assessment of the Timely Administration of Birth Dose Vaccines in Northern Nigeria and Associated Factors

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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.

The Role of General Attitudes and Perceptions Towards Vaccination on the Newly-Developed Vaccine: Results From a Survey on COVID-19 Vaccine Acceptance in China

Background

Vaccination has been considered one of the most effective public health interventions. In the context of the global epidemic of coronavirus disease 2019 (COVID-19), it remains unclear what role general vaccination attitudes and perceptions have on the acceptance of COVID-19 vaccine.

Objective

This study aims to explore the impact of general attitudes and perceptions toward vaccination on the acceptance of a newly developed vaccine, taking COVID-19 vaccines as an example.

Method

A cross-sectional survey was conducted among 2,013 Chinese adult participants. Generalized order logistic regression and path analysis models were used to analyze impacts of general attitudes and perceptions toward vaccination on the acceptance of the COVID-19 vaccine.

Results

The prevalence of hesitancy to vaccination in general is 49.9% among the Chinese adult population. General perceptions of vaccination were associated with corresponding perceptions of the COVID-19 vaccine. A “no hesitancy” attitude toward vaccination is a significant determinant (aOR = 1.77, 95% CI = 1.36–2.31) of future COVID-19 vaccination compared to vaccine refusers, and perceptions of COVID-19 vaccine remain a significant determinant for the acceptance of the COVID-19 vaccine. Path analysis indicates that perceptions of the importance and safety of vaccination have a positive overall effect on the acceptance of the COVID-19 vaccine, and that general perceptions of vaccination as a whole on each measure indirectly influence the acceptance of the COVID-19 vaccine.

Conclusion

General attitudes and perceptions toward vaccination were associated with those of the COVID-19 vaccine and future vaccination intention. To prepare for possible emergence of diseases in the future, routine health campaigns should be launched by relevant government departments and vaccination authorities to enhance the overall awareness and knowledge of vaccination among the public and to ensure optimal vaccination experience. In addition, targeted knowledge dissemination and mass mobilizations should be urged for newly developed vaccines when some specific infectious diseases emerge, such as COVID-19 at present.

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.

Assessment of vaccination timeliness and associated factors among children in Toke Kutaye district, central Ethiopia: A Mixed study

Introduction

Age inappropriate vaccination of children increases the rate of mortality and morbidity. All studies conducted in some areas of Ethiopia were only quantitative in nature and focused on the main cities ignoring rural communities.

Objective

The objective of this study is to assess vaccination timeliness and associated factors among children in Toke Kutaye district, central Ethiopia.

Methods

A community-based cross-sectional study with quantitative and qualitative data collection methods was used, for which simple random sampling was used to select 602 mothers/caregivers who have vaccinated children aged 12 to 23 months in the district. The collected data were entered into Epi-data version 3.1 and exported to SPSS version 23 for analysis. Bivariate analysis with a P-value of < 0.25 was used to select candidate variables for multivariate logistic regression. Adjusted odds ratio (AOR) with 95% CI and p-value < 0.05 were used to declare a significant association. Qualitative data responses were classified and then organized by content with thematic analysis.

Results

A total of 590 respondents responded to the interviews, making a response rate of 98%. In this study, 23.9% (95% CI: 20.4–27.7) of children aged 12–23 months had received all vaccines in the recommended time intervals. Urban residence (AOR: 3.15, 95% CI: 1.56–6.4), participation of pregnant women in conferences (AOR: 2.35, 95% CI: 1.2–4.57), institutional delivery (AOR: 2.5: 95% CI: 1.32–4.20), and sufficient knowledge of mothers (AOR: 3, 95% CI: 1.82–5.10) were significantly associated with the timeliness of childhood vaccination. Qualitative findings revealed that lack of knowledge and lack of information from mothers or caregivers, and inadequate communication with health workers hindered timely vaccination.

Conclusion

The overall timeliness of the child’s vaccination was low in this study. Residence, participation in a conference, place of delivery, and knowledge of the mothers were predictors of vaccination timeliness. Hence, promoting institutional delivery and increasing pregnant mothers awreness on vaccination timeliness through conference participation is compulsory.

Delays in routine childhood vaccinations and their relationship with parental vaccine hesitancy: a cross-sectional study in Wuxi, China

OBJECTIVES

This study aimed to examine childhood vaccination delay, explore the association between vaccination delay and parental vaccine hesitancy, and assess childhood vaccination delays during the coronavirus disease (COVID)-19 pandemic in China.

METHODS

This cross-sectional survey was conducted in Wuxi City. Participants were recruited from local vaccination clinics. Questionnaires were used to collect information about socio-demographics, vaccine hesitancy, and immunization clinic evaluations. Vaccination records were obtained from the Jiangsu Information Management System of Vaccination Cases.

RESULTS

Overall, 2728 participants were included. The coverage for seven category A vaccines (Expanded Program on Immunization (EPI)) was more than 95% at 24 months. The proportion of children vaccinated in a timely manner was the highest for the first dose of the hepatitis B vaccine (91.6%) and the lowest for the Bacillus-Calmette-Guerin vaccine (44.6%). More than 50% of the planned vaccinations were delayed in February and March 2020. The Vaccine Hesitancy Scale scores were not associated with vaccination delay (P = 0.842). Children's vaccination delays were negatively associated with parents who reported convenient access to clinics and satisfaction with immunization services (P = 0.020, P = 0.045).

CONCLUSIONS

EPI is highly successful in China. Despite vaccination delays due to the COVID-19 pandemic, coverage was recovered after lockdown restrictions were eased.

Trends and determinants of vaccination among children aged 06-59 months in Bangladesh: country representative survey from 1993 to 2014

Background

Vaccination has important consequences for childhood development, mortality, and inequalities in health and well-being. This research explores the trend of vaccinations coverage from 1993 to 2014 and determines the significant factors for vaccinations coverage in Bangladesh, considering geospatial, socioeconomic, and demographic characteristics.

Methods

This study uses a secondary dataset extracted from the Bangladesh Demographic and Health Survey (BDHS) from 1992 to 93 to 2014. The association between selected independent variables and vaccination coverage of children was examined through the Chi-square test. In addition, unadjusted and adjusted logistic regression approaches were applied to determine the effects of covariates on vaccination status by using the BDHS-2014 dataset.

Results

The results reveal that the trend of the vaccination coverage rate has gradually been increased over the study period. The coverage rate of BCG is observed maximum while the lowest for Measles vaccination among all types of vaccinations. The findings revealed that the significantly lower coverage of all vaccination had been observed in the Sylhet region. Children of higher educated mothers (OR 10.21; CI: 4.10–25.37) and father (OR 8.71; CI: 4.03–18.80), born at health facilities (OR 4.53; CI: 2.4–8.55) and whose mother has media exposure (OR 3.20; CI: 2.22–4.60) have more chance of receiving BCG vaccine. For DPT vaccination coverage, there is a significant difference from children whose mothers have primary (OR 1.7; CI: 1.35–2.15), secondary (OR 3.5; CI: 2.75–4.45), and higher (OR 9.6; CI: 5.28–17.42) educational qualification compared to children of illiterate mothers. Findings demonstrated that children born in wealthier households have a higher likelihood of being immunized against DPT, Polio, and Measles vaccination than children born in the poorest households.

Conclusions

The findings reveal that to enhance and make sustainable the overall country’s vaccination coverage, we should pay more attention to the mother’s education, socioeconomic condition, children’s age, birth order number, having media exposure, place of residence, and religion. The authors think that this finding would be helpful to accelerate the achievement target of Sustainable Development Goals (SDGs) for children’s health in Bangladesh.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11576-0.

Factors Associating Vaccination Delay among Jordanian Children under Two Years of Age

PURPOSE

This study examines the association between selected socio-demographic factors (gender, birth order, parents' educational levels, and parents' employment status) and reasons for vaccination delay among Jordanian children under two years of age.

DESIGN & METHODS

A cross-sectional, prospective study was conducted in the three comprehensive public health centres in Amman Governorate in Jordan from January-June, 2019. The electronic vaccination record was designed to collect socio- demographic information and reasons for vaccination delay in children. This data was collected from the medical records of those children.

RESULTS

The findings revealed that 150 (8.3%) children under two years of age were registered as vaccination-delayed cases. The factors associated with vaccination delay were age (Chi-square test [χ²] [6150] = 15.02, p-value [p] < 0.01), birth order (χ² [6150] = 15.02, p < 0.01), mother's educational level (χ² [2150] = 9.27, p < 0.05), and father's and mother's employment (χ² [2150] = 7.89, p < 0.05; χ² [2150] = 10.54, p < 0.01, respectively).

CONCLUSION

Timeliness of vaccination should be promoted to prevent illness outbreaks and provide specific protection for children, taking into consideration the significance of age and birth order.

PRACTICE IMPLICATIONS

Interventions and strategies need to implementation to reduce vaccination delay and improve timeliness.

Timeliness of Vaccination among Children Attending Immunization Clinic at a Tertiary Hospital in South-East Nigeria

Background

Timely vaccination of children is one of the most cost-effective interventions that ensure childhood survival. We determined the proportion of children who received timely vaccination and examined the factors associated with timely receipt of Bacillus Calmette Guerin (BCG) and third dose of pentavalent vaccine (Penta 3).

Methodology

We conducted a cross-sectional survey among 599 caregivers-infant pair aged less than 24months, attending the immunization clinic of a tertiary hospital in Nigeria, selected using systematic sampling methods. Using a structured questionnaire, we access the proportion of children who received timely vaccination, the relationship between the timely receipt of BCG, Penta 3 vaccine and infant/caregiver characteristics was examined using chi-square and multiple logistic regression at a 5% level of significance.

Results

The mean age of the respondents was 30.1±5.0 years. The majority (73.8%) had attained tertiary education, lived in an urban setting (90.9%), had received antenatal care during pregnancy (99.3%) and was delivered in a hospital (97.0%). About half of the children (52.9%) were male. About 18% of the caregivers reported missing scheduled immunization visits, due to forgetfulness (18%), child illness (14%) and being busy (5%). About 88% (482) of the children got their BCG vaccines on time, 91.1% got timely OPV0, however, only 29.5% of the newborns got HBV0 within 24 hours of birth. Only 65.7% and 65.0% received the timely measles-containing vaccine and yellow fever vaccine. None of the factors examined predicted timely receipt of BCG and Penta 3 vaccines.

Conclusion

Interventions that remind caregivers about the immunization schedules, could improve timely vaccination.

Effect of Mobile Phone Text Message Reminders on the Completion and Timely Receipt of Routine Childhood Vaccinations: Superiority Randomized Controlled Trial in Northwest Ethiopia

BACKGROUND

Nonattendance at vaccination appointments is a big challenge for health workers as it is difficult to track routine vaccination schedules. In Ethiopia, 3 out of 10 children have incomplete vaccination and the timely receipt of the recommended vaccines is low. Thus, innovative strategies are required to reach the last mile where mobile technology can be effectively utilized to achieve better compliance. Despite this promising technology, little is known about the role of text message-based mobile health interventions in improving the complete and timely receipt of routine childhood vaccinations in Ethiopia.

OBJECTIVE

This trial aimed to determine the effect of mobile phone text message reminders on the completion and timely receipt of routine childhood vaccinations in northwest Ethiopia.

METHODS

A two-arm, parallel, superiority randomized controlled trial was conducted in 9 health facilities in northwest Ethiopia. A sample size of 434 mother-infant pairs was considered in this trial. Randomization was applied in selected health facilities during enrollment with a 1:1 allocation ratio by using sealed and opaque envelopes. Participants assigned to the intervention group received mobile phone text message reminders one day before the scheduled vaccination visits. Owing to the nature of the intervention, blinding of participants was not possible. Primary outcomes of full and timely completion of vaccinations were measured objectively at 12 months. A two-sample test of proportion and log-binomial regression analyses were used to compare the outcomes between the study groups. A modified intention-to-treat analysis approach was applied and a one-tailed test was reported, considering the superiority design of the trial.

RESULTS

A total of 426 participants were included for the analysis. We found that a higher proportion of infants in the intervention group received Penta-3 (204/213, 95.8% vs 185/213, 86.9%, respectively; P<.001), measles (195/213, 91.5% vs 169/213, 79.3%, respectively; P<.001), and full vaccination (176/213, 82.6% vs 151/213, 70.9%, respectively; P=.002; risk ratio 1.17, 95% lower CI 1.07) compared to infants in the usual care group. Similarly, a higher proportion of infants in the intervention group received Penta-3 (181/204, 88.7% vs 128/185, 69.2%, respectively; P<.001), measles (170/195, 87.1% vs 116/169, 68.6%, respectively; P<.001), and all scheduled vaccinations (135/213, 63.3% vs 85/213, 39.9%, respectively; P<.001; risk ratio 1.59, 95% lower CI 1.35) on time compared to infants in the usual care group. Of the automatically sent 852 mobile phone text messages, 764 (89.7%) were delivered successfully to the participants.

CONCLUSIONS

Mobile phone text message reminders significantly improved complete and timely receipt of all recommended vaccines. Besides, they had a significant effect in improving the timely receipt of specific vaccines. Thus, text message reminders can be used to supplement the routine immunization program in resource-limited settings. Considering different contexts, studies on the implementation challenges of mobile health interventions are recommended.

TRIAL REGISTRATION

Pan African Clinical Trial Registry PACTR201901533237287; https://pactr.samrc.ac.za/TrialDisplay.aspx?TrialID=5839.

Vaccination coverage estimates and utilization patterns of inactivated enterovirus 71 vaccine post vaccine introduction in Ningbo, China

Background

In China, enterovirus 71 (EV71) is the major etiological agents of hand foot mouth disease that poses severe risks to children’s health. Since 2015, three inactivated EV71 vaccines have been approved for use. Previous studies indicated the high willingness of EV71 vaccination in eastern China. However, few studies have assessed coverage and utilization patterns of EV71 vaccine in China.

Methods

Children born during 2012–2018 were sampled and their records were abstracted from Ningbo childhood immunization information management system. Descriptive statistics characterized the study population and assessed coverage and timeliness for EV71 vaccination. Simultaneous administration patterns as well as type of EV71 vaccine used were also evaluated. Bivariate and multivariable analysis was used to examine the relationship of socio-demographic characteristics with vaccination coverage and timeliness.

Results

Of 716,178 children living in Ningbo. One hundred seventy-two thousand two hundred thirty-six received EV71 vaccine with a coverage rate of 24.05% and only 8.61% received vaccination timely. 21.97% of children received the complete two dose EV71 series but only 6.49% completed timely. Vaccination coverage and timeliness increased significantly from 2012 birth cohort to 2018 birth cohort. Relatively higher coverage and timeliness were observed in resident children, Inner districts, high socioeconomic areas and large-scaled immunization clinics. Of 329,569 doses of EV71 vaccine, only 5853(1.78%) doses were administered at the same day as other vaccines.

Conclusions

There is a need for increasing EV71 vaccination coverage and timeliness as well as eliminating disparities among different populations. Our study highlights the importance of simultaneous administration to increasing coverage and timeliness of EV71 vaccination.

Age-appropriate vaccination practice and associated factors among mothers of children aged less than one year in the pastoral community of Afar region, Ethiopia

Achieving and maintaining high-level immunization coverage is the priority of the health-care delivery system. However, any delay in receiving the vaccine leaves youngsters inadequately protected. Timely vaccination has scarcely been reported and given little attention in developing nations like Ethiopia, which hinders effective interventions. Therefore, this study aimed to assess age-appropriate vaccination practice and associated factors among mothers of children aged less than one year in the pastoral community. A community-based cross-sectional study has conducted among 340 mothers/caregivers of children aged less than one year in Samara-logia city administration. A systematic random sampling technique was employed to identify and enroll mothers-child paired. The logistic regression analysis had done to identify the factors associated with age-appropriate vaccination practice. The statistical association had measured, and a p-value < 0.05 was considered statistically significant. In this study, a total of 331 mothers/caregivers-child pairs participated with a response rate of 97.3%. The age-appropriate vaccination practice was 43.7% (95% CI, 38%, 49.5%). Mothers who had higher educational level (Adjusted odds ratio (AOR)) = AOR = 2.89, 95% CI (1.14, 7.3), antenatal care follow-up (AOR = 2.1, 95% CI (1.04, 4.1)), and had good knowledge on vaccination (AOR = 3.1, 95% CI (1.4, 6.78)) were associated with increased odds of age-appropriate vaccination practice.

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.

The trends of socioeconomic inequities in full vaccination coverage among children aged 12-23 months from 2000 to 2017: evidence for mitigating disparities in vaccination service in Zhejiang province

OBJECTIVE

This study aimed to evaluate the trends and changes in inequities in the completeness of the primary vaccination (CPV) scheduled before the first year of age among children aged 12-23 months, from 2000 to 2017. Methods: Data were extracted from five rounds of the provincial vaccination coverage survey (PVCS) in 2000, 2004, 2008, 2014 and 2017, respectively. The household income per month was used as an index of socioeconomic status for the inequity analysis. The concentration index (CI) was used to quantify the degree of inequity, and the decomposition approach was applied to quantify the contributions from independent factors to inequity in the CPV. Results: The CPV was significantly improved from 2000 to 2017, with 67.0% for the 2000 PVCS and 86.0% for the 2017 PCVS. The CI value decreased from 0.29839 for the 2000 round to 0.03601 for the 2017 round. The decomposition analysis indicated that independent variables such as birth order, ethnic group, mother's education, maternal employment status, residence, immigration status and the percentage of the total health spending allocated to public health could explain the inequity in the CPV in varying degrees. Conclusions: A sharp reduction in socioeconomic inequity in the CPV was observed from 2000 to 2017. Policy recommendations to reduce the inequality in the CPV should focus on children with the risk factors found in this study, for better outcome in full vaccination and long-lasting herd immunity.

Timeliness and completeness of routine childhood vaccinations in young children residing in a district with recurrent vaccine-preventable disease outbreaks, Jerusalem, Israel

BackgroundChildhood vaccination schedules recommend vaccine doses at predefined ages.AimWe evaluated vaccination completeness and timeliness in Jerusalem, a district with recurrent vaccine-preventable disease outbreaks.MethodsVaccination coverage was monitored by the up-to-date method (vaccination completeness at age 2 years). Timeliness of vaccination was assessed in children (n = 3,098, born in 2009, followed to age 48 months, re-evaluated at age 7 years) by the age-appropriate method (vaccine dose timeliness according to recommended schedule). Vaccines included: hepatitis B (HBV: birth, 1 month and 6 months); diphtheria, tetanus, acellular pertussis, polio, Haemophilus influenzae b (DTaP-IPV-Hib: 2, 4, 6 and 12 months); pneumococcal conjugate (PCV: 2, 4 and 12 months); measles-mumps-rubella/measles-mumps-rubella-varicella (MMR/MMRV: 12 months) and hepatitis A (HAV: 18 and 24 months).ResultsOverall vaccination coverage (2014 cohort evaluated at age 2 years) was 95% and 86% for MMR/MMRV and DTaP-IPV-Hib4, respectively. Most children (94%, 91%, 79%, 95%, 92% and 82%) were up-to-date for HBV3, DTaP-IPV-Hib4, PCV3, MMR/MMRV1, HAV1 and HAV2 vaccines at 48 months, but only 32%, 28%, 38%, 58%, 49% and 20% were vaccinated timely (age-appropriate). At age 7 years, the median increase in vaccination coverage was 2.4%. Vaccination delay was associated with: high birth order, ethnicity (higher among Jews vs Arabs), birth in winter, delayed acceptance of first dose of DTaP-IPV-Hib and multiple-dose vaccines (vs MMR/MMRV). Jewish ultra-Orthodox communities had low vaccination coverage.ConclusionsConsiderable vaccination delay should be addressed within the vaccine hesitancy spectrum. Delays may induce susceptibility to vaccine-preventable disease outbreaks; tailored programmes to improve timeliness are required.

Timely completion of vaccination and its determinants among children in northwest, Ethiopia: a multilevel analysis

BACKGROUND

Timely vaccination is key to prevent unnecessary childhood mortality from vaccine-preventable diseases. Despite the substantial efforts to improve vaccination completeness, the effort towards timeliness of vaccination is limited with non-attendance and delays to vaccination appointments remaining a big challenge in developing countries. There is also a limited evidence on timeliness of vaccination. Therefore, this study aimed to determine the magnitude and associated factors for timely completion of vaccination among children in Gondar city administration, north-west, Ethiopia.

METHOD

This study employed a community-based cross sectional study design. A sample size of 821 children aged 12 to 23 months were considered. Two stages random sampling technique was used to select study subjects. To account the effect of clustering, bivariable and multivariable multilevel logistic regression analysis were applied. The measures of association estimates were expressed as adjusted odds ratio (AOR) with their 95% confidence intervals (CIs).

RESULTS

Of the 774 children included for analysis, 498 (64.3%) were fully vaccinated while 247 (31.9%) were fully vaccinated on-time. Caregivers who had secondary education and above (AOR = 2.391; 95% CI: 1.317-4.343), from richest households (AOR = 2.381; 95% CI: 1.502-3.773), children whose mother attended four or more ante natal care visits (AOR = 2.844; 95% CI: 1.310-6.174) and whose mother had two or more post natal care visits (AOR = 2.054; 95%CI:1.377-3.063) were positively associated with on-time full vaccination. In contrary, caregivers aged above 35 years (AOR = 0.469; 95 % CI: 0.253-0.869], being vaccinated at health post (AOR = 0.144; 95%CI: 0.048-0.428) and travelling more than 30 min to the vaccination site (AOR = 0.158; 95%CI: 0.033-0.739) were negatively associated with on-time full vaccination. The random effects indicated that 26% of the variability in on-time full vaccination was attributable to differences between communities.

CONCLUSION

In this study, untimely vaccination was found to be high. Different individual and contextual factors were found to be associated with on-time full vaccination. Therefore, tailored strategies have to be designed and implemented to address people and the communities where they live. Moreover, timeliness of vaccination should be considered as important indicator of the immunization program performance in Ethiopia.

EPI immunization coverage, timeliness and dropout rate among children in a West Cameroon health district: a cross sectional study

BACKGROUND

Monitoring of the expanded program on immunization's performance is not only limited to routine periodic reports but equally includes surveys. Based on unpublished national EPI surveillance data from the past 5 years in Cameroon, the Foumban health district has reported a high number of vaccine preventable disease suspected cases. Contradictory information on the immunization coverage in this district exists from both administrative data and published literature. As a result, the objective of this study was to estimate the immunization coverage and dropout rate in age group 12-23 months and timeliness in age group 0-59 months among children in Foumban Health District (Cameroon), in 2018.

METHOD

This was a descriptive cross-sectional study targeting randomly selected children aged 0-59 months from Foumban health district. Data were collected by trained and supervised surveyors using a pretested questionnaire to describe the immunization coverage, timeliness and dropout rate in eighty clusters of about thirty buildings selected by stratified random sampling in July 2018.

RESULTS

In total, 80 clusters covering 2121 buildings were selected and all were reached (100%). A total of 1549 (81.2%) households accepted to participate in the survey and 1430 children aged 0-59 months including 294 (20.6%) aged 12-23 months were enrolled into the study. Of these 1430 children, 427 [29.9 (27.4-32.2)%] aged 0-59 months were vaccinated with evidence. In the age group 12-23 months, the immunization coverage with evidence of BCG, DPT-Hi + Hb 3 and measles/rubella were 28.6(23.4-33.9)%, 22.8 (18.1-27.6)% and 14.3 (10.3-18.1)% respectively. Within age group 0-59 months; the proportion of children who missed their vaccination appointments increased from 23.3 to 31.7% for the vaccine planned at birth (BCG) and last vaccine planned (Measles/Rubella) for the EPI program respectively. In age group 12-23 months; the specific (DPT-Hi + Hb1-3) and general (BCG-Measles/Rubella) dropout rates of vaccination with evidence were 14.1 and 50.0% respectively.

CONCLUSION

Documented immunization coverage, dropout rate and timeliness in Foumban Health district are lower than that targeted by the Cameroon EPI. Competent health authorities have to take necessary actions to ensure the implementation of national guidelines with regards to children access to immunization. Also, studies have to be conducted to identify determinants of low immunization coverage and delays in immunization schedules as well as high dropout rates.

Age-appropriate vaccination coverage and its determinants for the polio containing vaccine 1-3 and measles-containing vaccine doses in Zhejiang province, China: A community-based cross-sectional study

Background: This study aimed to evaluate the age-appropriate coverage and its associated risk factors for the primary vaccination of Polio containing vaccine (PCV) and measles-containing vaccine (MCV) through the secondary use of the 2018 Zhejiang provincial coverage survey among children aged 12-23 months. Methods: Data were collected through structured pre-tested Chinese version questionnaire by face-to-face interview among 770 mothers whose children aged 12-23 months. Age-appropriate vaccination coverage was measured using Chinese vaccination schedule recommendation. Bivariate and multivariate logistic regression models were adopted to identify determinants of the age-inappropriate vaccination. Results: The age-appropriate vaccination coverage of PCV1, PCV2, PCV3, and MCV was 88.8%, 80.8%, 73.6%, and 75.7%, respectively. The risk factors associated with the age-inappropriate vaccination of PCV 1-3 dose and MCV included child's gender, birthplace, living area, maternal education level, immigration status, monthly household income, participation of the pregnant women's seminar, antenatal care follow-up, knowledge on vaccination. Conclusion: The proportions of age-appropriate vaccination coverage were low compared with the up-to-date coverage. Modifiable factors were associated with age-inappropriate vaccinations. Vaccination interventions should consider identified modifiable factors to improve age-appropriate vaccination coverage.

Analyzing the Urban-Rural Vaccination Coverage Disparity through a Fair Decomposition in Zhejiang Province, China

Objectives: Exploring determinants underlying disparities in full vaccination coverage (FVC) can contribute to improved immunization interventions. FVC and its risk factors in Zhejiang province have been studied, yet the determinants explaining the rural-urban disparity in FVC have not been studied. This study aimed to disentangle the factors explaining rural-urban disparities in FVC of vaccine doses scheduled during the first year of life in Zhejiang province. Methods: We used data from a vaccination coverage survey among children aged 24-35 months conducted in 2016. The outcome measure was full vaccination status, and the grouping variable was the area of residence. Descriptive statistics were used to analyze the FVC and rural-urban residence across the exposure variables. The Fairlie decomposition technique was used to decompose factors contributing to explaining the FVC disparity. Results: There were 847 children included in this study, of which 49.6% lived in a rural area. FVC was 94% in rural areas and 85% in urban areas. A disparity of 9% to the advantage of the rural areas and the exposure variables explained 81.1% of the disparity. Maternal factors explained 49.7% of the explained disparity with education, occupation, and ethnicity being the significant contributors to the explained disparity. Children's birth order and immigration status contributed somewhat to the explained inequality. Conclusion: There was a significant disparity in FVC in Zhejiang province, a disadvantage to the urban areas. Policy recommendations or health interventions to reduce the inequality should be focused on eliminating poverty and women's illiteracy, targeted at migrant children or children from minority ethnicities.

Infant, maternal and demographic predictors of delayed vaccination: A population-based cohort study

BACKGROUND

Receiving vaccines at or close to their due date (vaccination timeliness) is a now key measure of program performance. However, studies comprehensively examining predictors of delayed infant vaccination are lacking. We aimed to identify predictors of short and longer-term delays in diphtheria-tetanus-pertussis (DTP) vaccination by dose number and ethnicity.

METHODS

Perinatal, notification, death and immunisation databases were linked for 1.3 million births in 2000-11 from two Australian states (Western Australia and New South Wales), with follow-up data until 2013. Ordinal logistic regression was used to estimate adjusted relative risks (RR) by degree of delay. Separate models were constructed for each vaccine dose and for Aboriginal and non-Aboriginal children.

RESULTS

Each dose-specific cohort included at least 49,000 Aboriginal and 1.1 million non-Aboriginal children. Delayed receipt was more common among Aboriginal than non-Aboriginal children (eg for the first dose of DTP [DTP1] 19.4 v 8.1%). Risk factors for delayed vaccination were strongest for DTP1, and delayed receipt of DTP1 was a key driver of subsequent delays; every week DTP1 was delayed was associated with a 1.6 to 2-fold increased risk of delayed DTP2 receipt. For DTP1, ≥3 previous pregnancies (the only factor more strongly associated with longer than shorter delays; RR ≥5 compared to no previous pregnancies), and children born to mothers <20 years of age (RR ≥2 compared to ≥35 years) were at highest risk of delay. Other independent predictors were prematurity, maternal smoking during pregnancy, and being born in Western Australia (if Aboriginal) or another country in the Oceania region.

CONCLUSION

The sub-populations at risk for delayed vaccination we have identified are likely generalisable to other high-income settings. Measures to improve their dose 1 timeliness, particularly for children with older siblings, are likely to have significant flow-on benefits for timeliness of later doses.

Text message reminders to improve infant immunization in Guatemala: A randomized clinical trial

OBJECTIVE

Millions of infants worldwide remain under-immunized and at risk for unnecessary morbidity and mortality. Text messaging may offer a low-cost solution. We aimed to evaluate text message reminders to improve infant immunization in Guatemala.

METHODS

A randomized clinical trial was conducted at four public health clinics in rural and urban Guatemala. Infants ages six weeks to six months presenting for the first visit of the primary immunization series were randomly and equally allocated to an intervention or usual care group. Intervention participants were sent three text reminders before the second and third vaccine visits. The main outcome was timeliness of the second and third visits of the primary immunization series.

RESULTS

Of 1088 families approached for enrollment between March to November 2016, 871 were eligible and 720 (82.7%) participated; only 54 families did not own a cell phone. Due to country-wide vaccine shortages, visit completion was used as a proxy for overall immunization coverage. In intention to treat analysis, both intervention and usual care groups had high rates of visit completion, but intervention participants presented on the scheduled date more often (151 [42.2%] of 358 intervention vs. 111 [30.7%] of 362 usual care participants for visit 2, p = 0.001, and 112 [34.0%] of 329 intervention vs. 90 [27.0%] of 333 usual care participants for visit 3, p = 0.05). Intervention caregivers were significantly more likely to want to receive future text message reminders for vaccines and other appointments and were more willing to pay for these reminders.

CONCLUSION

Caregivers who were sent text message reminders in urban and rural Guatemala were less delayed for their child's immunization visits and reported high user satisfaction. Text message reminders may be an effective tool to increase infant vaccination coverage in low-income settings by reminding parents to vaccinate.

TRIAL REGISTRATION

NCT02567006 at clinicaltrials.gov.

Age-appropriate vaccination coverage and its associated factors for pentavalent 1-3 and measles vaccine doses, in northeast Ethiopia: A community-based cross-sectional study

BACKGROUND

In Ethiopia, there are limited studies on age-appropriate vaccinations that children received at the recommended specific ages. Therefore, we assessed age-appropriate vaccinations coverage and its associated factors among children 12 to 23 months of age in Menz Lalo district, northeast Ethiopia.

METHODS

A community-based cross-sectional study was conducted in Menz Lalo district from March to April/2018 among 417 mothers/caregivers with children 12 to 23 months of age using simple random sampling technique. Data were collected using a pretested structured questionnaire. Information about children's vaccination status was collected from vaccination cards. Age-appropriate vaccination coverage was measured using World Health Organization vaccination schedule recommendation. Data was entered into Epi-Info7 software and exported to SPSS-20 for analysis. Four consecutive logistic regression models were performed to identify factors associated with age-inappropriate vaccinations. A P-value of ≤ 0.05 was considered to state statistically significant associations.

RESULTS

Age-appropriate vaccination coverage was 39.1% (95% CI: 34.3 to 44) for pentavalent 1, 36.3% (95% CI: 31.6 to 41.5) for pentavalent 2, 30.3% (95% CI: 25.6 to 35) for pentavalent 3 and 26.4% (95% CI: 21.7 to 31) for measles vaccine doses. Age-inappropriate pentavalent 1-3 vaccinations was associated with being male sex (AOR: 0.47, 95% CI: 0.29-0.74), lack of telephone (AOR: 2.2, 95% CI: 1.4-3.6), lack of usual caretaker (AOR: 2.6, 95% CI: 1.3-5.2), unplanned pregnancy (AOR: 1.9, 95% CI: 1.1-3.5), missing pregnant women's conference (AOR: 2.7, 95% CI: 1.3-5.7), decreasing birth order (AOR: 0.34, 95% CI: 0.17-0.68) and insufficient knowledge (AOR: 2.7, 95% CI: 1.6-4.4).

CONCLUSION

The proportions of age-appropriate vaccination coverage were low in the study area. Modifiable factors were associated with age-inappropriate vaccinations. Vaccination interventions should consider identified modifiable factors to improve age-appropriate vaccinations coverage.

Factors associated with missed and delayed DTP3 vaccination in children aged 12 - 59 months in two communities in South Africa, 2012 - 2013

BACKGROUND

Although immunisation services are available to all children in South Africa (SA), many children miss or have delays in receiving vaccines. There are limited data on factors associated with missed or delayed vaccination in children in this setting.

OBJECTIVES

To assess vaccination coverage and factors associated with missed and delayed diphtheria-tetanus-pertussis vaccine third dose (DTP3) vaccination in children aged 12 - 59 months in two SA communities.

METHODS

We used data from household-level healthcare utilisation surveys conducted in Soweto in 2012 and in Pietermaritzburg in 2013. Information on vaccination status was recorded from the Road to Health cards or vaccination history from clinics for children aged <5 years. Factors associated with missed or delayed DTP3 vaccination were assessed using unconditional logistic regression.

RESULTS

Of a total of 847 eligible children aged 12 - 59 months, 716 had available vaccination information. Overall DTP3 vaccination coverage was high for both sites: 90.6% in Pietermaritzburg and 93.9% in Soweto. However, 32.6% and 25.2% of DTP3 vaccinations were delayed (received after 18 weeks of age) in Pietermaritzburg and Soweto, respectively. The median delay for DTP3 vaccinations was 4.7 weeks (interquartile range 1.7 - 23.0). Factors associated with delayed DTP3 vaccination included being born in 2010 (adjusted odds ratio (aOR) 3.0, 95% confidence interval (CI) 1.4 - 6.3) or 2011 (aOR 2.7, 95% CI 1.3 - 5.7) compared with being born in 2008, probably due to vaccine shortages; a low level of education of the primary caregiver, with children whose caregivers had completed secondary education having lower odds of delayed vaccination (aOR 0.5, 95% CI 0.3 - 0.9) than children whose caregivers only had primary education; and maternal HIV status, with unknown status (aOR 3.5, 95% CI 1.6 - 7.6) associated with higher odds of delay than positive status. Factors associated with missed DTP3 vaccination (not vaccinated by 12 months of age) included two or more children aged <5 years in a household (aOR 2.4, 95% CI 1.2 - 4.9) compared with one child, and household monthly income <ZAR500 (aOR 3.4, 95% CI 1.1 - 11.4) compared with ≥ZAR2 000.

CONCLUSIONS

Despite high overall DTP3 coverage observed in two communities, many vaccinations were delayed. Vulnerable groups identified in this study should be targeted with improved vaccination services to enhance uptake and timeliness of vaccination.

Vaccination timeliness and delay in low- and middle-income countries: a systematic review of the literature, 2007-2017

Background: Traditional measurements of vaccine coverage at specific ages can mask poor vaccine timeliness. However, optimal measurement of timing is unclear due to variations in countries’ recommended vaccination schedules and lack of a commonly accepted standard for “timeliness”. We conducted a systematic review of literature on vaccine timeliness and delay in low- and middle-income countries from 2007 to 2017.

Methods: A search of articles published between January 1 2007 and December 31 2017, was performed in PubMed, EBSCOhost, and Embase.

Results: 67 papers were included, of which 83% used a categorical measure of delay and 41% evaluated continuous delay. The most common age at assessment was 1 month, with earlier age benchmarks typically used with birth doses.

Conclusions: Categorical definitions of vaccination timing vary widely, with benchmarks of delay varying from days to weeks to months. Use of a continuous measure of vaccine delay may be more informative and comparable.

Reliability and validity of a survey to identify vaccine hesitancy among parents in Changxing county, Zhejiang province

BACKGROUND

To evaluate the validity and reliability of a survey to identify vaccine hesitancy among parents.

METHODS

Cross-sectional survey of parents of 19-35 month old children was conducted in Changxing County, Zhejiang Province, through a questionnaire developed for the survey of the vaccine hesitancy. Construct validity was assessed by linking parental responses to their child's immunization record. The association between mean% of days of under-immunization and the parental socio-demographics and the individual item response was explored via the univariate and multivariate analyses. Factor analysis was applied to confirm survey sub-domains and Cronbach's α to determine the internal consistency reliability of sub-domain scales.

RESULTS

We approached 336 households while 285 of them agreed to participate in this study. Education level and the parental 'score of vaccination hesitancy' were significantly associated with the mean% of days of under-immunization. Cronbach's coefficients for the 3 sub-domain scales created by re-grouping the questionnaire's items were 0.71, 0.83, and 0.72, respectively.

CONCLUSIONS

The survey represented a valid and reliable instrument to identify VHPs and it could help to screen parents to receive an intervention aimed at increasing acceptance of vaccinations.

Validity of Maternal Recall to Assess Vaccination Coverage: Evidence from Six Districts in Zhejiang Province, China

Background: Although recall-based data are collected by survey when the vaccination records are not available, the preferred estimates remain the record-based ones due to the limited validity of recall-based data. However, the evidence on validity of maternal recalls is limited and varied across vaccine types. To close the gaps, we validated the maternal recall on vaccination against record-based data in six districts in Zhejiang Province, China. Methods: We used a cross-sectional survey of about 648 households with mothers who delivered in the last 12 months prior to the survey in October 2017, from six districts in Zhejiang Province. Vaccination status on five vaccine types scheduled before 12 months of age were collected through maternal recall and vaccination records. The level of agreement and recall bias between the two resources, the sensitivity and specificity of maternal recall were evaluated. Risk factors for maternal recall bias were also identified through logistic regression model for each type of vaccine. Results: The level of agreement between recall and record was above 90% across vaccine types, with the recall bias ranged from 2.2% to 9.7%. Recall bias due to over-reporting was slightly higher than that due to under-reporting. Recall bias was positively associated with high parity, home delivery, younger mothers, mothers with low education, and migrant mothers. Conclusions: This study indicated most of the vaccination status across vaccine types was accurately identified through maternal recall and supported the use of maternal recall to estimate the vaccination coverage as an alternative in the absence of record-based data.

Hepatitis B Vaccination among 1999⁻2017 Birth Cohorts in Zhejiang Province: The Determinants Associated with Infant Coverage

This study aimed to investigate the coverage of hepatitis B vaccine (Hep B) and its completeness and timeliness for birth cohorts from 1999 to 2017 in Zhejiang province, East China. Demographic characteristics and vaccination records of Hep B of children born from 1 January 1999 to 31 June 2017 were extracted from the Zhejiang provincial immunization information system. The timeliness of the first dose of Hep B (Hep B1) was defined as the proportion of children who received the Hep B1 within 24 h after birth among the target population. The completeness of Hep B was defined as the proportion of children who completed the three-dose series of Hep B before 7 years of age. The demographic characteristics of the target population were described. The coverage of each dose of Hep B, the timeliness of Hep B1, and the completeness of Hep B for each birth cohort were described. A logistic regression model was applied to detect the determinants of the timeliness of Hep B1 and the completeness of Hep B vaccination. The coverage of Hep B1 increased from 90.3% to 98.3%, the coverage of Hep B2 increased from 88.8% to 96.1%, and the coverage of Hep B3 increased from 86.4% to 94.2%. The timeliness of Hep B1 increased from 80.3% to 91.3%. The completeness of Hep B increased from 81.3% to 91.5%. The determinants of timeliness of Hep B1 included children’s delivery place, immigration status, maternal education level, and economic development level of resident area. The determinants of completeness of Hep B included children’s delivery place, immigration status, maternal education level, economic development level of resident area, maternal occupation, and frequency of vaccination service. Zhejiang province had achieved significant improvements in the timely administration of Hep B1 and the completeness of Hep B. To accelerate progress toward additional reductions in the transmission of hepatitis B virus, further efforts need to be focused on improving the timeliness of Hep B1 vaccination and reducing the drop-outs among disadvantaged children with the risk factors identified in this study.

Factors affecting age-appropriate timeliness of vaccination coverage among children in Lebanon

Background: The effect of immunization does not only depend on its completeness, but also on its timely administration. Routine childhood vaccinations schedules recommend that children receive the vaccine doses at specific ages. This article attempts to assess timeliness of routine vaccination coverage among a sub-sample of children from a survey conducted in 2016. Methods: This analysis was based on data from a cross-sectional multistage cluster survey conducted between December 2015 and June 2016 among caregivers of children aged 12-59 months in all of Lebanon using a structured survey questionnaire. The analysis used Kaplan-Meier curves and logistic regression to identify the predictors of age-appropriate immunization. Results: Among the 493 randomly selected children, timely administration of the third dose of polio vaccine, diphtheria-tetanus-pertussis (DTP)-containing vaccine and hepatitis B (HepB) vaccine occurred in about one-quarter of children. About two-thirds of children received the second dose of a measles-containing vaccine (MCV) within the age interval recommended by the Expanded Programme on Immunization (EPI). Several factors including socio-demographic, knowledge, beliefs and practices were found to be associated with age-appropriate vaccination; however, this association differed between the types and doses of vaccine. Important factors associated with timely vaccination included being Lebanese as opposed to Syrian and being born in a hospital for hepatitis B birth dose; believing that vaccination status was up-to-date was related to untimely vaccination. Conclusions: The results suggest that there is reason for concern over the timeliness of vaccination in Lebanon. Special efforts need to be directed towards the inclusion of timeliness of vaccination as another indicator of the performance of the EPI in Lebanon.

Measles vaccination coverage, determinants of delayed vaccination and reasons for non-vaccination among children aged 24-35 months in Zhejiang province, China

Background

This study was aimed to assess the coverage of two doses of measles vaccine and identify the determinants of the delayed vaccination.

Methods

A cluster survey among 1386 children aged 24–35 months was conducted. Characteristics on demographic and socio-economic and vaccination records was collected. The overall coverage was defined as the proportion of children receiving the first dose of measles vaccination and the second dose of measles vaccination by 24 months of age. The age-appropriate coverage was defined as the proportion of children receiving the measles vaccine doses within one month after its relevant due date. Timeliness was evaluated with the Kaplan-Meier analysis. Cox proportional hazard regression was adopted to identify determinants of the delayed vaccination.

Results

The overall coverage was 96.9% for the first dose of measles vaccine and 93.9% for the second dose of measles vaccine. The age-appropriate coverage of the first and the second dose of measles vaccine was 76.6 and 68.2%, respectively. Household having more than one child, non-local children were associated with the delayed vaccination for the first and the second dose of measles vaccine. Children delivered at home, younger mothers, low maternal education background, mothers with a fixed job, and low household income were associated with the delayed vaccination for the second dose of measles vaccine.

Conclusions

The coverage of measles vaccine had been improved for both the first and the second dose, while the timeliness still needed improvement. We suggested the policy-makers pay more attention to the reasons for non-vaccination and determinants of delayed vaccination when planning efforts to ensure the high age-appropriate coverage of measles vaccination.

Measuring childhood vaccination acceptance of mother in Zhejiang province, East China

BACKGROUND

The aim of this study was to evaluate the vaccine hesitancy among mothers and examine risk factors associated with mother's intention to vaccination in Zhejiang province.

METHODS

A provincial sample of mothers of children aged 24-35 months was surveyed (N = 770) in August, 2017. Demographic information, perception on the past childhood vaccination, knowledge on vaccination, information searches and needs, trust in different institutions on vaccination were collected. Based on the theory of planned behaviour (TPB), attitudes toward vaccination, perceived social support, perceived behavioural control as well as mothers' intention to immunize their child were constructed. Descriptive statistics were generated for all variables. Univariate and multivariate analyses were performed to identify differences between mothers who had strong intentions to immunize their children in future and those with weaker intentions.

RESULTS

Of the participants, 79.6% had a positive attitudes towards vaccination, 77.5% had a high perceived social support, 63.2% had a high perceived behaviour control and 87.3% strongly intended to have their child vaccinated. Strong intention to vaccination was significantly associated with the positive behavioral attitudes [adjusted odds ratios (AOR) = 3.2, 95% CI: 2.3-5.7], the high perceived social support (AOR = 2.8, 95% CI: 1.8-3.6), the perceived ease of undergoing vaccination (AOR = 2.1, 95% CI: 1.6-3.3), respectively.

CONCLUSIONS

It was recommended that interventions focused on trust-building, promoting social norms, changing the negative attitude would be effective to enhance the maternal acceptance on vaccination.

Routine vaccination coverage of children aged 1-7 years in Zhejiang province, China

BACKGROUND

This study was to evaluate the coverage, completeness and timeliness of routine vaccination among children aged 1-7 years in Zhejiang province.

METHODS

Demographic information and immunization records of 4613160 children born from Jan 1, 2010 to Dec 31, 2016 were extracted from Zhejiang provincial immunization information system (ZJIIS) on Dec 31, 2017. Vaccination coverage for each vaccine dose and completeness of different vaccine series were calculated by birth cohort, immigration status, and geographic area. The timeliness of vaccine doses scheduled before 12 months of age for the 2016 birth cohort was also examined Results: Coverage of all the vaccine doses scheduled before 12 months of age and its completeness reached the target goal of 90%. The coverage and completeness decreased substantially in vaccinations scheduled after 12 months old, and most of them were below 90%. The coverage and timeliness estimates of migrant children was lower than those of resident children and the coverage of WenZhou (WZ), Zhoushan (ZS) and Lishui (LS) was lower than other cities across all the birth cohorts. Despite high coverage rates for all antigens by age 12 months, there was a very large range of percent of vaccination delay when comparing different antigens scheduled in the first year of life for the 2016 birth cohort.

CONCLUSIONS

This study demonstrated the success and improvement of immunization program in Zhejiang province, and identified some challenges. Strategies such as assessment, feedback, incentives, and exchange program, reminder/recall activity, home visits, immunization requirement for school's enrollment could be used to reach a higher coverage of the population.

The effect of maternal decisional authority on children's vaccination in East Asia

Even though they are important determinants for increasing vaccination rates in advanced and developing nations alike, maternal capacity and decisional authority have not been fully elucidated in diverse countries and cultural spheres. This study examined the effects of South Korean, Chinese, and Japanese mothers' health literacy, self-efficacy, mass media use, and decisional authority on their children's vaccination after adjustment for their socioeconomic statuses. Computer-assisted web interviews were conducted with married women in their 20s-40s of South Korean, Chinese, or Japanese nationality (n = 1,571). Dependent variables were generated for the following four vaccinations: BCG, diphtheria+pertussis+tetanus (DPT), poliomyelitis (polio), and measles. For statistical processing, cases where all four types of vaccines had been recorded were scored as 1 and other cases were processed as 0. According to the results of the pooled model, we found that for East Asian mothers, decisional authority, self-efficacy, and health literacy all increased the likelihood that they would vaccinate their children. Furthermore, women who searched for health information through media such as the radio were more likely to vaccinate their children. However, when elaborate analyses were conducted by country, there were considerable differences in those characteristics by country. Therefore, this study showed that it is necessary to establish locally tailored strategies in order to raise vaccination rates in the Global Vaccine Action Plan. This study also showed that social contexts must be taken into consideration in order to raise vaccination rates.

An Overview of Coverage of BCG Vaccination and Its Determinants Based on Data from the Coverage Survey in Zhejiang Province

To assess the Bacille Calmette-Guérin (BCG) vaccination coverage in Zhejiang province and to investigate predictors of the BCG vaccination, we used data from the 2017 Zhejiang provincial coverage survey. Demographic and immunization data on the selected children, their mothers, and their families were also collected by using a pre-tested questionnaire. BCG scars were verified among children who were available at the moment of survey. Coverage of BCG and other expanded program on immunization (EPI) vaccines scheduled before the first year of life was calculated. BCG coverage through the scar assessment and timeliness of BCG were also presented. Multivariate analyses of the predictors associated with the BCG vaccination and its timeliness were conducted separately. In total, 1393 children agreed to participate in the survey and presented the immunization cards. Of them, the coverage of BCG was 92.0% and 88.3% received the BCG within the first 28 days after birth. Besides this, 1282 out of the 1393 children were screened for the BCG scars and 97.1% of them had developed the scars. The multivariable logistic regression analyses indicated that hospital delivery, higher maternal education, a mother with no job, and a resident child were positively associated with the higher BCG vaccination coverage and its timely administrations. BCG coverage was optimal and it was administered in a timely manner. The majority of children vaccinated with BCG developed scars. Tailored interventions should be more greatly focused on and targeted to children with the risk factors identified in this study.

Assessment of on-time vaccination coverage in population subgroups: A record linkage cohort study

Reported infant vaccination coverage at age 12 months in Australia is >90%. On-time coverage of the 2-4-6 month schedule and coverage in specific populations is rarely reported. We conducted a population-based cohort study of 1.9 million Australian births, 1996-2012, combining individual birth and perinatal records with immunisation records through probabilistic linkage. We assessed on-time coverage across 13 demographic and perinatal characteristics of diphtheria-tetanus-pertussis vaccines (DTP) defined as vaccination 14 days prior to the scheduled due date, to 30 days afterwards. On-time DTP vaccination coverage in non-Aboriginal infants was 88.1% for the 2-month dose, 82.0% for 4-month dose, and 76.7% for 6-month dose; 3-dose coverage was 91.3% when assessed at 12 months. On-time DTP coverage for Aboriginal infants was 77.0%, 66.5%, and 61.0% for the 2-4-6 month dose; 3-dose coverage at 12 months was 79.3%. Appreciable differences in on-time coverage were observed across population subgroups. On-time coverage in non-Aboriginal infants born to mothers with ≥3 previous pregnancies was 62.5% for the 6-month dose (47.9% for Aboriginal infants); up to 23.5 percentage points lower than for first-borns. Infants born to mothers who smoked during pregnancy had coverage 8.7-10.3 percentage points lower than infants born to non-smoking mothers for the 4- and 6-month dose. A linear relationship was apparent between increasing socio-economic disadvantage and decreasing on-time coverage. On-time coverage of the 2-4-6 month schedule is only 50-60% across specific population subgroups representing a significant avoidable public health risk. Aboriginal infants, multiparous mothers, and those who are socio-economically disadvantaged are key groups most likely to benefit from targeted programs addressing vaccine timeliness.

Analysis of the effects of individual- and community- level predictors on migrant children's primary immunization in Yiwu city, east China

BACKGROUND

To evaluate the effects of a wide range of individual- and community-level factors on migrant children's primary immunization.

METHODS

Migrant children aged 13-24 months (born from 1 June 2013 to 31 May 2014) were surveyed in Yiwu city, in June 2015. Social-demographic factors and vaccination records were collected. Five factors at community-level including community wealth, distance to the nearest immunization clinic, maternal education, antenatal clinic (ANC) visits, and hospital delivery were constructed. The relationship between individual- and community-level factors and a child's vaccination status for Chinese primary immunization were evaluated by logistic regression model and the adjusted odds ratio (AOR) with the p-values and 95% confidence interval (CI) were calculated.

RESULTS

The community wealth (aOR:1.4; 95% CI:1.1-2.7), the community maternal education (aOR:1.8; 95% CI:1.4-4.5), the community ANC visits (aOR:1.8; 95% CI:1.3-2.8), and the community hospital delivery (aOR:2.2; 95% CI:1.6-4.8) were positively associated with the completeness of primary immunization, while community distance to the nearest immunization clinic was negatively associated with the completeness of primary immunization (aOR:0.7; 95% CI:0.5-0.9). The coverage of completeness of primary immunization was higher among children living in rural areas than those living in urban areas (aOR:1.7; 95% CI: 1.3-3.1).

CONCLUSIONS

In order to achieve better vaccination coverage among migrant children in Yiwu, as well as to close the gaps and disparities of acceptability and accessibility in childhood vaccination in urban areas, policy makers should design interventions based on the factors addressed in this study.

Initiation and completion rates of inactivated hepatitis A vaccination among children born between 2005 and 2014 in Zhejiang province, east China

OBJECTIVES

To evaluate the initiation and completion and timeliness of inactivated hepatitis A vaccine (HAV-I) series, to identify the missed opportunities for HAV-I series, and to examine determinants associated with the completion of HAV-I.

METHODS

Children born from 1 January 2005 to 31 December 2014 and registered in Zhejiang provincial immunization information system (ZJIIS), were enrolled in this study. Descriptive statistics were used to describe the initiation and completion, the timeliness and the missed opportunities for HAV-I. Logistic regression analysis was applied to explore the determinants of the completeness of HAV-I.

RESULTS

The initiation rate of HAV-I increased from 8.1% for the 2005 birth cohort to 13.2% for the 2014 birth cohort. The completion rate of HAV-I increased from 4.2% for the 2005 birth cohort to 7.8% for the 2014 birth cohort. The timeliness rate of the 1^st dose of HAV-I increased from 38.2% for the 2005 birth cohort to 57.9% for the 2014 birth cohort. The timeliness rate the 2^nd dose of HAV-I increased from 17.3% for the 2005 birth cohort to 35.3% for the 2014 birth cohort. 78.3% of the children who did not initiated any hepatitis A vaccine, had at least one immunization clinic visit after their 18^th month of age. 36.0% of the children who received the 1^st dose of HAV-I but did not receive the 2^nd dose, had at least one immunization clinic visit after 6 months from the date of receiving the 1^st dose of HAV-I. The determinants including year of birth, socio-economic development level of municipals, place of delivery, receipt of MMR/VarV were associated with the completion of HAV-I series.

CONCLUSION

Although the initiation and completion of HAV-I series had improved in recent years, these indicators were still lower than those for other vaccines scheduled at the similar age. It is important for providers to identify every opportunity for HAV-I vaccination and to assure that children get protection from this vaccine-preventable disease.

How often do children receive their vaccinations late, and why?

OBJECTIVES

To assess vaccination timeliness, risk factors associated with delays and the reasons for delayed vaccinations among children below the age of 3 years in Jeddah, Kingdom of Saudi Arabia.

METHODS

This is a cross-sectional study conducted in Jeddah, Saudi Arabia during the period of May 2016 to August 2017. Data were obtained from parents of children under the age of 3 years using a structured questionnaire comprised of questions about sociodemographics, physical well-being of the child and the reasons that are used to justify delayed vaccinations. Vaccinations were considered delayed if they occurred more than 30 days after the time designated on the primary vaccination schedule. Logistic regression was used to assess the risk factors for vaccination delays.

RESULTS

The study included 351 children. Delayed vaccinations were observed in 85/351 (24.2%) of the sample. Delays were noted to occur most frequently for Measles, Mumps, Rubella vaccine (MMR), seconddose of meningococcal conjugate quadrivalent vaccine (MCV4), second  dose of oral polio vaccine (OPV) and fourth  dose of pneumococcal conjugate vaccine (PCV) in 19/125 (15.2%) of the sample. Traveling at the time of vaccination was the most common delay reason and was reported in 31/142 (21.3%) of the sample.

CONCLUSION

Adherence to vaccination is fairly common in this part of the country. However, vaccination delays are still present and should be addressed to improve health care.

Delayed measles vaccination of toddlers in Canada: Associated socio-demographic factors and parental knowledge, attitudes and beliefs

Delaying vaccination increases the period of vulnerability of children against vaccine-preventable diseases. We used a nationally representative sample of Canadian two-year-old children to explore factors associated with delays in the uptake of the first dose of measles-containing vaccine, recommended in Canada for children at 12 months of age. Distribution of delays was determined using data from the 2013 Childhood National Immunization Coverage Survey. Logistic regression was used to examine sociodemographic factors and knowledge, attitudes and beliefs (KAB) associated with the two outcomes of interest: delays of one to six months (vaccination at 13 to 18 months of age) and delays of seven to 18 months (vaccination at 19 to 23 months of age). Overall, 69% (95% confidence interval [CI] 67–71) of children received their first valid dose on time. Twenty-nine percent (95% CI 27–31) and 11% (95% CI 9–12) of children were unvaccinated before turning 13 and 16 months of age, respectively. Factors associated with delays of one to six months were being a girl, being born outside Canada, and the jurisdiction of residence. Being from a single-parent family, being born outside Canada and the jurisdiction of residence were associated with delays of seven to 18 months, suggesting that potential barriers might be at play. Associations between KAB and vaccination delays indicate that vaccine hesitancy could contribute to measles vaccination delays in Canada. Barriers in accessing vaccination services and the role of vaccine hesitancy in timely vaccination must be better understood to reduce vaccination delays in toddlers in Canada.

Vaccination of infants aged 0 to 11 months at the Yaounde Gynaeco-obstetric and pediatric hospital in Cameroon: how complete and how timely?

BACKGROUND

Vaccination is a major, but simple and cost effective public health intervention in the prevention of infectious diseases, especially in children. Nowadays, many children still miss scheduled vaccines in the Extended Program of Immunization (EPI) or are being vaccinated after the recommended ages.This study was aimed at assessing vaccination completeness and timeliness in children aged 0 to 11 months attending the vaccination clinic of the Yaounde Gynaeco-Obstetric and Pediatric Hospital.

METHODS

This was an observational cross-sectional study over a period of 3 months (1st February to 30th April 2016). 400 mothers were interviewed and their children's vaccination booklets analyzed. Information on the children and the parents was collected using a pretested questionnaire. Data analysis was done using SPSS version 20 software. Bivariate and multivariate analysis with logistic regression was done to assess the determinants of completeness and timeliness.

RESULTS

A total of 400 mother-infant pairs were sampled. The vaccination completeness rate was 96.3%. This rate varied between 99.50% for BCG and 94.36% for IPV. Most of the children were born at the Yaounde Gynaeco-Obstetric and Pediatric hospital where they were regularly receiving their vaccines. The proportion of correctly vaccinated infants was 73.3%. The most differed vaccines were BCG, PCV13 and IPV. Factors influencing immunization completeness were the father's profession and the mother's level of education.

CONCLUSIONS

Despite the high immunization coverage, some children did not complete their EPI vaccines and many of them took at least one vaccine after the recommended age.

Timeliness of Childhood Primary Immunization and Risk Factors Related with Delays: Evidence from the 2014 Zhejiang Provincial Vaccination Coverage Survey

Background: this study aimed to assess both immunization coverage and timeliness, as well as reasons for non-vaccination, and identity the risk factors of delayed immunization, for the vaccines scheduled during the first year of life, in Zhejiang province, east China. Methods: A cluster survey among children aged 24-35 months was conducted. Demographic information and socio-economic characteristics of the selected child, the mother, and the household were collected. Immunization data were transcribed from immunization cards. Timeliness was assessed with Kaplan-Meier analysis for each vaccine given before 12 months of age, based on the time frame stipulated by the expanded program on immunization of China. Cox proportional hazard regression was applied to identify risk factors of delayed immunization. Results: A total of 2772 eligible children were surveyed. The age-appropriate coverage ranged from 25.4% (95% CI: 23.7-27.0%) for Bacillus Calmette-Guerin (BCG) to 91.3% (95% CI: 90.2-92.3%) for the first dose of oral poliomyelitis vaccine (OPV1). The most frequent reason for non-vaccination was parent's fear of adverse events of immunization. Delayed immunizations were associated with mother having a lower education level, mother having a job, delivery at home, increasing number of children per household, and having a lower household income. Conclusions: Although the timeliness of immunization has improved since 2011, necessary steps are still needed to achieve further improvement. Timeliness of immunization should be considered as another important indicator of expanded program on immunization (EPI) performance. Future interventions on vaccination coverage should take into consideration demographic and socio-economic risk factors identified in this study. The importance of adhering to the recommended schedule should be explained to parents.

Evaluating Childhood Vaccination Coverage of NIP Vaccines: Coverage Survey versus Zhejiang Provincial Immunization Information System

Vaccination coverage in Zhejiang province, east China, is evaluated through repeated coverage surveys. The Zhejiang provincial immunization information system (ZJIIS) was established in 2004 with links to all immunization clinics. ZJIIS has become an alternative to quickly assess the vaccination coverage. To assess the current completeness and accuracy on the vaccination coverage derived from ZJIIS, we compared the estimates from ZJIIS with the estimates from the most recent provincial coverage survey in 2014, which combined interview data with verified data from ZJIIS. Of the enrolled 2772 children in the 2014 provincial survey, the proportions of children with vaccination cards and registered in ZJIIS were 94.0% and 87.4%, respectively. Coverage estimates from ZJIIS were systematically higher than the corresponding estimates obtained through the survey, with a mean difference of 4.5%. Of the vaccination doses registered in ZJIIS, 16.7% differed from the date recorded in the corresponding vaccination cards. Under-registration in ZJIIS significantly influenced the coverage estimates derived from ZJIIS. Therefore, periodic coverage surveys currently provide more complete and reliable results than the estimates based on ZJIIS alone. However, further improvement of completeness and accuracy of ZJIIS will likely allow more reliable and timely estimates in future.