Higher pertussis hospitalization rates in indigenous Australian infants, and delayed vaccination

Timeliness of Childhood Vaccinations Following Strengthening of the Second Year of Life (2YL) Immunization Platform and Introduction of Catch-Up Vaccination Policy in Ghana

Strengthening routine immunization systems to successfully deliver childhood vaccines during the second year of life (2YL) is critical for vaccine-preventable disease control. In Ghana, the 18-month visit provides opportunities to deliver the second dose of the measles-rubella vaccine (MR2) and for healthcare workers to assess for and provide children with any missed vaccine doses. In 2016, the Ghana Health Service (GHS) revised its national immunization policies to include guidelines for catch-up vaccinations. This study assessed the change in the timely receipt of vaccinations per Ghana's Expanded Program on Immunizations (EPI) schedule, an important indicator of service quality, following the introduction of the catch-up policy and implementation of a multifaceted intervention package. Vaccination coverage was assessed from household surveys conducted in the Greater Accra, Northern, and Volta regions for 392 and 931 children aged 24-35 months with documented immunization history in 2016 and 2020, respectively. Age at receipt of childhood vaccines was compared to the recommended age, as per the EPI schedule. Cumulative days under-vaccinated during the first 24 months of life for each recommended dose were assessed. Multivariable Cox regression was used to assess the associations between child and caregiver characteristics and time to MR2 vaccination. From 2016 to 2020, the proportion of children receiving all recommended doses on schedule generally improved, the duration of under-vaccination was shortened for most doses, and higher coverage rates were achieved at earlier ages for the MR series. More timely infant doses and caregiver awareness of the 2YL visit were positively associated with MR2 vaccination. Fostering a well-supported cadre of vaccinators, building community demand for 2YL vaccination, sustaining service utilization through strengthened defaulter tracking and caregiver-reminder systems, and creating a favorable policy environment that promotes vaccination over the life course are critical to improving the timeliness of childhood vaccinations.

Role of leadership and incentive-based programs in addressing vaccine hesitancy in India

The current study goes beyond the popular 5Cs model of vaccine hesitancy to explore perceived social norms, role of leadership and the role of incentive-based intervention for improving the likelihood of vaccination, in a population-representative sample of adults in India (N = 1129). We investigated differences in socio-demographic status, perceived descriptive norms like vaccine behaviours, beliefs, experience and perceived injunctive norms like community and political leadership within the context of the COVID-19 pandemic are related to vaccination. Further, we examined the role of incentive-based intervention as a potentially salient predictor of adults' vaccine uptake. The study is based on a cross-sectional survey conducted in July-November 2021, which included questions about impacts of pandemic collected by phone call interview from adults' beneficiaries of Government free food schemes, across 11 states in India. The data include 81 % vaccinated and 19 % vaccine hesitant participants, with a higher proportion of business or self-employed (53.1 %) as vaccine hesitant. We performed the t-test to assess the variation between vaccinated and vaccine hesitant adults, and Exploratory Factor Analysis to uncover the underlying dimension of vaccine hesitancy. Subsequently, Binary Logistic Regression model probed the factors associated with likelihood of vaccination uptake. In contrast to the prevailing evidence, results demonstrated community and political leadership has significant negative impact on vaccination (p-value < 0.06, 95 % CI, 0.57-1.01). Incentive-based intervention offer a vital leverage to enhance positive attitude towards vaccination (p-value < 0.05, 95 % CI, 1.01-1.80). The results thus broadly highlight the limited role of political and community leaders in leveraging their influence on vaccination, the role of timely, accurate information, applications of telemedicine as an important tool to provide healthcare and the need for optimal design of incentive-based vaccination programs recommended by trusted sources.

Increasing Uptake of Maternal Pertussis Vaccinations through Funded Administration in Community Pharmacies

Although maternal pertussis vaccination is recommended, uptake is suboptimal in New Zealand (NZ), despite full funding in general practice and hospitals. We determined whether funding maternal pertussis vaccination in community pharmacy increases its uptake. Pertussis vaccination during pregnancy was compared between non-contiguous, demographically similar regions of NZ. The pertussis vaccine was funded at pharmacies from Nov 2016 in one NZ region (Waikato), but not in comparator regions (Northland, Hawkes Bay). Vaccinations during pregnancy were determined from the National Immunisation Register, general practice and pharmacy claims data, and a maternity database. Comparisons were made using adjusted odds ratios (OR) and 95% confidence intervals (CI) for Nov 2015 to Oct 2016 versus Nov 2016 to Oct 2019. The odds of pregnancy pertussis vaccination increased in the post-intervention versus pre-intervention period with this increase being larger (p = 0.0014) in the intervention (35% versus 21%, OR = 2.07, 95% CI 1.89–2.27) versus the control regions (38% versus 26%, OR = 1.67, 95% CI 1.52–1.84). Coverage was lower for Māori versus non-Māori, but increased more for Māori in the intervention versus control regions (117% versus 38% increase). It was found that funding maternal pertussis vaccination in pharmacy increases uptake, particularly for Māori women. Measures to increase coverage should include reducing barriers to vaccines being offered by non-traditional providers, including pharmacies.

The Challenge of Achieving Immunity Through Multiple-Dose Vaccines in Madagascar

Administration of many childhood vaccines requires that multiple doses be delivered within a narrow time window to provide adequate protection and reduce disease transmission. Accurately quantifying vaccination coverage is complicated by limited individual-level data and multiple vaccination mechanisms (routine and supplementary vaccination programs). We analyzed 12,541 vaccination cards from 6 districts across Madagascar for children born in 2015 and 2016. For 3 vaccines-pentavalent diphtheria-tetanus-pertussis-hepatitis B-Haemophilus influenzae type b vaccine (DTP-HB-Hib; 3 doses), 10-valent pneumococcal conjugate vaccine (PCV10; 3 doses), and rotavirus vaccine (2 doses)-we used dates of vaccination and birth to estimate coverage at 1 year of age and timeliness of delivery. Vaccination coverage at age 1 year for the first dose was consistently high, with decreases for subsequent doses (DTP-HB-Hib: 91%, 81%, and 72%; PCV10: 82%, 74%, and 64%; rotavirus: 73% and 63%). Coverage levels between urban districts and their rural counterparts did not differ consistently. For each dose of DTP-HB-Hib, the overall percentage of individuals receiving late doses was 29%, 7%, and 6%, respectively; estimates were similar for other vaccines. Supplementary vaccination weeks, held to help children who had missed routine care to catch up, did not appear to increase the likelihood of being vaccinated. Maintaining population-level immunity with multiple-dose vaccines requires a robust stand-alone routine immunization program.

Timeliness of childhood vaccinations in the Philippines

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

Pre- and post-intervention study examining immunisation rates, documentation, catch-up delivery and the impact of a dedicated immunisation service at a tertiary paediatric hospital

AIM

To explore immunisation rates and catch-up delivery to children admitted to hospital before and after an immunisation service was commenced.

METHODS

This pre- and post-intervention study examined 300 admissions prior to (cohort 1) and 300 following (cohort 2) the introduction of an immunisation service. Immunisation rates, documentation, catch-up delivery and accuracy of the Australian Immunisation Register (AIR) were examined.

RESULTS

On admission, 75% (cohort 1) and 89% (cohort 2) were up-to-date with immunisations. Immunisation history was documented in the medical record in 78% and requirement for catch-up documented in 10%. AIR was incorrect in one-third of cases. By 3 months following discharge, 28% (cohort 1) and 64% (cohort 2) of patients were immunised.

CONCLUSIONS

Children admitted to hospital have lower immunisation rates than the national average. Documentation was poor, opportunities for catch-up were missed and AIR is error-prone. Catch-up rates increased following the introduction of an immunisation service.

Implementation and adherence of routine pertussis vaccination (DTP) in a low-resource urban birth cohort

INTRODUCTION

Reliable information on rates of up-to-date coverage and timely administration of routine childhood immunisations are critical for guiding public health efforts worldwide, yet prospective observation of vaccination programmes within individual communities is rare. Here, we provide a longitudinal analysis of the directly observed administration of a three-dose primary vaccination series to infants in a low-resource community in Lusaka, Zambia.

METHODS

Throughout 2015, we recruited a longitudinal birth cohort of mother/infant pairs (initial enrolment, 1981 pairs; attending, 1497 pairs) from the periurban informal settlement of Chawama compound, located in Lusaka, Zambia. We prospectively monitored the administration of scheduled diphtheria-tetanus-pertussis (DTP) vaccinations across the first 14-18 weeks of life. We analysed study attendance and vaccine coverage, both overall and stratified by age group. We employed Kaplan-Meier analyses to estimate delays in age-appropriate administration of vaccine doses. We also assessed schedule timing violations, including early and compressed dose administration.

RESULTS

At study completion, first dose (DTP1) rates were high (92.9% of attending), whereas third dose completion (DTP3) rates were far lower (61.9%). Missed vaccinations and study dropout both contributed to the low DTP3 completion rates. DTP1 was administered very late (at or after 10 weeks) to 61 infants (4.1%). DTP1 was administered too early to 64 infants (4.3%), and 77 (5.1%) received consecutive doses below the minimum recommended spacing of 28 days.

CONCLUSIONS

We observe substantial individual variation in the timing of early childhood DTP doses, though following this birth cohort proved challenging. Our results indicate that timely administration of both DTP1 and DTP3 remains a challenge in this community. These directly-observed, individual-based results provide an important counterpoint to more course-grained, survey-based national and province estimates of up-to-date vaccine coverage. This study also highlights the challenges of vaccine hesitancy and suboptimal utilisation of (no-cost) healthcare services in a low-resource urban setting.

Timeliness of routine vaccination among children and determinants associated with age-appropriate vaccination in Mongolia

INTRODUCTION

Routine vaccination at the recommended age is crucial to minimize the risk of acquiring vaccine preventable diseases. This study aimed to assess the proportion of children receiving routine immunization at the recommended age and determinants of timely (age-appropriate) vaccination in Mongolia.

MATERIAL AND METHOD

A total of 879 eligible children aged 12-23 months were included in this study. We investigated age-appropriate administration of Bacillus Calmette-Guerin vaccine (BCG); hepatitis B vaccine (Hep B); oral polio vaccine (OPV); pentavalent vaccine; and measles, mumps, and rubella vaccine (MMR) using Kaplan-Meier method. Multilevel logistic regression with random intercept at cluster level was used to assess the determinants of age-appropriate vaccination.

RESULTS

Overall, the crude vaccination coverage for routine vaccinations were above 90% for all vaccines except MMR1 which was 86.0% (95% CI, 83.6-88.2). While the first dose of almost all the vaccines given at birth; BCG, Hep B, and OPV0, were administered in a timely manner, a substantial proportion of second and third doses of these vaccines were not given in a timely manner with age-appropriate vaccination coverage ranging from 35.9% (32.8-39.1%) for MMR1 to 67.7% (64.5-70.7%) for OPV1 respectively. Factors associated with age-appropriate administration of the investigated vaccines included socio-economic status of household, religion of household heads, area of residence, owning mobile phone, and season of childbirth. For instance, children belonging to households from richer wealth quintile had higher possibilities of getting age-appropriate OPV1-OPV3, PE1-PE3 and MMR1 vaccines compared to those from the poorest household wealth quintile.

CONCLUSION

Our findings suggest that the commonly used indicator 'crude vaccination coverage' could be supplemented by 'age-appropriate vaccination' to help to identify gaps in timely vaccinations and stimulate interventions in Mongolia. Factors such as household wealth quintile, place of residence and religion associated with timely vaccination in our study could be considered to promote effective intervention aiming to improve adequate vaccination coverage.

A Qualitative Study of Views and Experiences of Women and Health Care Professionals about Free Maternal Vaccinations Administered at Community Pharmacies

Background: A policy to extend funding of maternal pregnancy influenza and pertussis vaccinations to community pharmacies could address low pregnancy vaccine uptake. The policy has been implemented in one region in New Zealand. This study explored the views and experiences of women eligible for the vaccines and health care professionals regarding funded maternal vaccinations in pharmacy. Methods: Women in late pregnancy or with an infant, and midwives, pharmacists, and general practice staff were selected purposively and interviewed regarding maternal vaccinations and the new policy, including their awareness and views of the funded vaccinations in pharmacies, and how this policy worked in practice. Enablers and barriers to vaccination by pharmacists were explored. Interviews were transcribed and analysed using a framework approach. Results: Fifty-three interviews were conducted. Most women and health care professionals viewed funded maternal vaccinations in pharmacies positively with respect to increasing awareness and providing delivery options. Many women received messages from pharmacies. Most pharmacies used posters, leaflets and/or verbal explanation to pregnant women to raise awareness of the vaccinations. Not all pharmacies provided these vaccinations, and frontline staff could help to raise awareness. Conclusion: Funded maternal vaccinations in pharmacies are generally well accepted and provide an opportunity to increase uptake and prevent disease.

Home-based records and vaccination appointment stickers as parental reminders to reduce vaccination dropout in Indonesia: A cluster-randomized controlled trial

INTRODUCTION

Limited evidence is available about the effectiveness of strategies to remind caregivers when to bring children back for future vaccinations in low- and middle-income country settings. We evaluated the effectiveness of two reminder strategies based on home-based vaccination records (HBR) in Indonesia.

METHODS

In this cluster-randomized controlled trial involving 3616 children <1 year of age, 90 health facilities were randomly assigned to either a control group or one of two intervention groups: (1) HBR-only group, where healthcare workers provided an HBR to any child without an HBR during a vaccination visit and instructed the caregiver to keep it at home between visits, or (2) HBR + sticker group, where, in addition to HBR provision, healthcare workers placed vaccination appointment reminder stickers on the HBR. The primary outcome was receipt of the third dose of diphtheria-tetanus-pertussis-containing vaccine (DTPcv3) within 7 months and the secondary outcome was receipt of a timely DTPcv3 dose.

RESULTS

Control group DTPcv3 coverage was 81%. In intention-to-treat analysis, neither intervention group had significantly different DTPcv3 coverage compared with the control group (RR = 0.94, 95% confidence interval [CI] 0.87; 1.02 for HBR-only group; RR = 0.97, 95% CI 0.90; 1.04 for HBR + sticker group) by study end. However, children in the HBR + sticker group were 50% more likely to have received a DTPcv3 vaccination (RR = 1.46, 95% CI 1.02, 2.09) within 60 days of DTPcv1 vaccination, compared with children in the control group; children in the HBR-only group were not more likely to have done so (RR = 1.05, 95% CI 0.71, 1.55).

DISCUSSION

Reminder stickers had an immediate effect on coverage by improving the proportion of children who received a timely DTPcv3 dose but no effect on the proportion who received DTPcv3 after 7 months. Coupling reminder stickers with strategies to address other reasons why children do not return for vaccination visits should be further explored.

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.

Timeliness and factors associated with rotavirus vaccine uptake among Australian Aboriginal and non-Aboriginal children: A record linkage cohort study

OBJECTIVES

Rotavirus vaccines (RV), included in Australia's National Immunisation Program from mid-July 2007, are unique in strict time limits for administration. Here, we report on timeliness of RV uptake, compare cumulative RV coverage to age 12 months with DTPa, and assess factors associated with receipt of RV among Aboriginal and non-Aboriginal children.

METHODS

Birth records for 681,456 children born in two Australian states in 2007-2012 were probabilistically linked to national immunisation records. We assessed on-time coverage (defined as receipt of vaccine dose between 4 days prior to scheduled date and the recommended upper limit) for RV and compared this to diphtheria-tetanus-pertussis (DTPa) vaccine. Logistic regression modelling was used to assess independent determinants of receipt of RV.

RESULTS

Compared to non-Aboriginal infants, on-time RV coverage was lower for all doses among Aboriginal infants. Post the upper age limit of RV dose2, DTPa dose2 coverage increased by 9-16% to ≥90%, whereas RV coverage remained around 77% (Aboriginal) and 85% (non-Aboriginal). Compared to first-born children, the adjusted odds of receiving ≥1 RV dose if born to a mother with ≥3 previous births was 0.30 (95%CI: 0.27-0.34) among Aboriginal, and 0.53 (95%CI: 0.51-0.55) among non-Aboriginal children. Prematurity (<33 weeks), low birthweight (<1500 g), maternal age <20 years, maternal smoking during pregnancy and living in a disadvantaged area were independently associated with decreased vaccine uptake.

CONCLUSIONS

Aboriginal children are at greater risk of rotavirus disease than non-Aboriginal children and delayed vaccine receipt is substantially higher. Although specific programs targeting groups at risk of delayed vaccination might improve RV coverage, relaxation of upper age restrictions is most readily implementable, and its overall risk-benefit should be evaluated.

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

Objective

Delayed vaccination increases the susceptibility window for vaccine preventable diseases. Our analysis estimates the proportion of children between 10 and 23 months of age with delayed vaccination in India and the associated socio-demographic, maternal and child related factors.

Methods

We used individual level data from the National Family and Health Survey 4, conducted in 2015–2016. The primary outcome of the study was delayed vaccination for BCG, DPT- 1st dose and Measles. Delayed vaccination for each vaccine was defined as administration of the vaccine dose after 28 days of the minimum recommended age, as per the national immunization schedule in India. We estimated the proportion of children with delayed vaccination for each vaccine and used multivariable logistic regression to explore associated factors.

Findings

In the current analysis, 23.1%, 29.3% and 34.8% of children aged 10 to 23 months had delayed vaccination for BCG, DPT-1st dose and Measles respectively. Children from Muslim families (aOR 1.36 for BCG; aOR 1.45 for DPT-1; aOR 1.26 for Measles); birth weight < 2000 g (aOR 2.33 for BCG; aOR 1.53 for DPT-1; aOR 1.36 for Measles) had higher odds of delayed vaccination. Lower maternal education and belonging to a family from lower wealth quintile had higher odds of delayed vaccination. Children of mothers who had tetanus toxoid immunization during pregnancy had lower odds of delayed vaccination (aOR 0.69 for BCG; aOR 0.76 for DPT-1; aOR 0.78 for Measles).

Conclusion

The proportion of children with delayed vaccination is high in India. Vaccine timeliness should be a core indicator of the immunization program with greater focus on groups with higher chances of delayed vaccination i.e. home birth, low birth weight new-borns, poorer households, children of mothers with lower education and children from Muslim families.

Baseline incidence of adverse birth outcomes and infant influenza and pertussis hospitalisations prior to the introduction of influenza and pertussis vaccination in pregnancy: a data linkage study of 78 382 mother-infant pairs, Northern Territory, Australia, 1994-2015

We conducted probabilistic data linkage of three population datasets for the Northern Territory (NT), Australia, to describe the incidence of preterm births, stillbirths, low birthweight and small for gestational age (SGA) per 1000 NT births; and influenza and pertussis hospitalisations per 1 00 000 NT births in infants <7 months of age, in a pre-maternal vaccination era. The Perinatal Trends dataset (1994-2014) formed the cohort of 78 382 births. Aboriginal mother-infant pairs (37%) had disproportionately higher average annual rates (AR) for all adverse birth outcomes compared to their non-Aboriginal counterparts; rate ratios: preterm births 2.2 (AR 142.4 vs. 64.7); stillbirths 2.3 (AR 10.8 vs. 4.6); low birthweight 2.9 (AR 54 vs. 19); and SGA 1.7 (AR 187 vs. 111). Hospitalisation (2000-2015) and Immunisation Register datasets (1994-2015), showed that influenza hospitalisations (n = 53) and rates were 42.3 times higher in Aboriginal infants (AR 254 vs. 6); and that pertussis hospitalisations (n = 37) were 7.1 times higher in Aboriginal infants (AR 142.5 vs. 20.2) compared to non-Aboriginal infants. These baseline data are essential to assess the safety and effectiveness of influenza and pertussis vaccinations in pregnant women from the NT. Remote living Aboriginal women and infants stand to benefit the most from these vaccines.

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.

Exploring factors impacting early childhood health among Aboriginal and Torres Strait Islander families and communities: protocol for a population-based cohort study using data linkage (the 'Defying the Odds' study)

INTRODUCTION

Empirical evidence on family and community risk and protective factors influencing the comparatively high rates of potentially preventable hospitalisations and deaths among Aboriginal and Torres Strait Islander infants and children is limited. As is evidence on geographical variation in these risks. The 'Defying the Odds' study aims to explore the impact of perinatal outcomes, maternal social and health outcomes and level of culturally secure service availability on the health outcomes of Western Australian (WA) Aboriginal infants and children aged 0-5 years.

METHODS AND ANALYSIS

The study combines a retrospective cohort study that uses state-wide linked health and administrative data from 12 data sources for multiple generations within Aboriginal families in WA, with specifically collected survey data from health and social services supporting Aboriginal families in regions of WA. Data sources include perinatal/birth registration, hospital, emergency department, mental health services, drug and alcohol service use, mortality, infectious disease notifications, and child protection and family services. Multilevel regression models will be used to examine the intensity of admissions and presentations, mortality, intensity of long stays and morbidity-free survival (no admissions) for Aboriginal children born in WA in 2000-2013. Relationships between maternal (and grand-maternal) health and social factors and child health outcomes will be quantified. Community-level variation in outcomes for Aboriginal children and factors contributing to this variation will be examined, including the availability of culturally secure services. Online surveys were sent to staff members at relevant services to explore the scope, reach and cultural security of services available to support Aboriginal families across selected regions of WA.

ETHICS AND DISSEMINATION

Ethics approvals have been granted for the study. Interpretation and dissemination are guided by the study team's Aboriginal leadership and reference groups. Dissemination will be through direct feedback and reports to health services in the study and via scientific publications and policy recommendations.

Vaccination Coverage and Timelines Among Children 0-6 Months in Kinshasa, the Democratic Republic of Congo: A Prospective Cohort Study

Objectives The Democratic Republic of Congo (DR Congo) is one of the ten countries, which accounts for 60% of unvaccinated children worldwide. The aim of this study was to assess predictors of incomplete and untimely immunization among a cohort of infants recruited at birth and followed up through 24 weeks in Kinshasa. Methods Complete immunization for each vaccine was defined as receiving all the recommended doses. Untimely immunization was defined as receiving the given dose before (early) or after (delayed) the recommended time window. Infants not immunized by the end of the follow-up time were considered missing. Multivariate hierarchical model and generalized logistic model were used to assess the independent contribution of each socio-economic and demographic factors considered to complete immunization and timeliness, respectively. Results Overall, of 975 infants from six selected clinics included in the analysis 84.7% were fully immunized the three doses of DTP or four doses of Polio by 24 weeks of age. Independently of the vaccine considered, the strongest predictor of incomplete and untimely immunization was the clinic in which the infant was enrolled. This association was strengthened after adjustment for socio-economic and demographic characteristics. Education and the socio-economic status also were predictive of completion and timeliness of immunization in our cohort. Discussion In conclusion, the strongest predictor for incomplete and untimely immunization among infants in Kinshasa was the clinics in which they were enrolled. The association was likely due to the user fee for well-baby clinic visits and its varying structure by clinic.

Undervaccination with diphtheria, tetanus, and pertussis vaccine: National trends and association with pertussis risk in young children

BACKGROUND

The high coverage for ≥3 pertussis vaccine doses among Taiwanese children might not imply timely vaccination. Recently, resurgence of pertussis and challenges with availability of DTaP-IPV-Hib prompted this study.

METHODS

In the 1996-2012 national birth cohort, we calculated the prevalence and days of undervaccination against pertussis by age 36 months. We also compared the odds of undervaccination in each laboratory-confirmed pertussis patient at ages 3-35 months with sex-, residence-, and age-matched controls from the general population, using conditional logistic regression.

RESULTS

The prevalence of undervaccination was 60.6% (median 16 days) and decreasing (p < 0.0001). Among 145 cases and 2,900 controls, 58 (40.0%) and 721 (24.9%) were undervaccinated (OR 2.28, 95% CI 1.57-3.31). The attributable risk percent was 22.5% (95% CI 14.5-27.9).

CONCLUSIONS

Undervaccination was decreasing. Approximately up to one-fifth pertussis cases in children aged 3-35 months could have been prevented with on-time vaccination.

Immunisation timeliness in a cohort of urban Aboriginal and Torres Strait Islander children

BACKGROUND

To evaluate immunisation coverage, timeliness and predictors of delayed receipt in urban Australian Indigenous children during the first 18 months of life.

METHODS

Cross-sectional retrospective analysis of data collected from 140 Australian Indigenous children aged < 5 years at the time of enrolment in a prospective cohort study on respiratory illness between 14 February 2013 and 28 January 2015. Children were recruited through an urban community primary health care centre in the Northern suburbs of Brisbane, Queensland.

RESULTS

The proportion of children with completed immunisation schedules was 50 of 105 (47.6%) at 7 months, 30 of 85 (35.3%) at 13 months and 12 of 65 (18.5%) at 19 months. Timely receipt of diphtheria-tetanus-pertussis decreased from 78.4% at 2 months of age to 63.7 and 59.3% at 4 and 6 months respectively. Amongst the 105 parents/guardians with children ≥7 months at enrolment, 71 (67.6%) incorrectly reported their child's immunisation status. Delayed vaccine receipt was significantly associated (p ≤0.05) with having multiple children in the household, mother's unemployment and premature birth.

CONCLUSIONS

Coverage and timeliness among this population is suboptimal and decreases as children age. Parent/guardian reporting of vaccination status was unreliable. Children of unemployed mothers and those with multiple siblings should be targeted to improve community immunisation timeliness due to a greater risk of vaccination delay. High quality trials, conducted in several settings to account for the diversity of Australian Indigenous communities are urgently needed to identify culturally appropriate, effective and sustainable strategies to improve immunisation targets in children.

Vaccination Timeliness in Children Under India's Universal Immunization Program

BACKGROUND

India has the highest number of deaths among children younger than 5 years of age globally; the majority are from vaccine preventable diseases. Untimely vaccination unnecessarily prolongs susceptibility to disease and contributes to the burden of childhood morbidity and mortality, yet there is scarce literature on vaccination delays. The aim of this study is to characterize the timeliness of childhood vaccinations administered under India's routine immunization program using a novel application of an existing statistical methodology.

METHODS

This study utilized the district level household and facility survey data, 2008 from India using vaccination data from children with and without immunization cards. Turnbull estimator of the cumulative distribution function was used to estimate the probability of vaccination at each age. Timeliness of Bacille Calmette-Guerin (BCG), all 3 doses of diphtheria, pertussis and tetanus vaccine (DPT) and measles-containing vaccine (MCV) were considered for this analysis.

RESULTS

Vaccination data on 268,553 children who were 0-60 months of age were analyzed; timely administration of BCG, DPT3 and MCV occurred in 31%, 19% and 34% of children, respectively. The estimated vaccination probability plateaued for DPT and BCG around the age of 24 months, whereas MCV uptake increased another 5% after 24 months of age. The 5-year coverage of BCG, DPT3 and MCV in Indian children was 87%, 63% and 76%, respectively.

CONCLUSIONS

Lack of timely administration of key childhood vaccines, especially DPT3 and MCV, remains a major challenge in India and likely contributes to the significant burden of vaccine preventable disease-related morbidity and mortality in children.

The Mobile Solutions for Immunization (M-SIMU) Trial: A Protocol for a Cluster Randomized Controlled Trial That Assesses the Impact of Mobile Phone Delivered Reminders and Travel Subsidies to Improve Childhood Immunization Coverage Rates and Timeliness in Western Kenya

Background

Text message (short message service, SMS) reminders and incentives are two demand-side interventions that have been shown to improve health care–seeking behaviors by targeting participant characteristics such as forgetfulness, lack of knowledge, and transport costs. Applying these interventions to routine pediatric immunizations may improve vaccination coverage and timeliness.

Objective

The Mobile Solutions for Immunization (M-SIMU) trial aims to determine if text message reminders, either with or without mobile phone–based incentives, sent to infant’s parents can improve immunization coverage and timeliness of routine pediatric vaccines in rural western Kenya.

Methods

This is a four-arm, cluster, randomized controlled trial. Villages are randomized to one of four study arms prior to enrollment of participants. The study arms are: (1) no intervention (a general health-related text message will be texted to this group at the time of enrollment), (2) text message reminders only, (3) text message reminders and a 75 Kenyan Shilling (KES) incentive, or (4) text message reminders and a KES200 incentive. Participants assigned to study arms 2-4 will receive two text message reminders; sent 3 days before and one day before the scheduled immunization visit at 6, 10, and 14 weeks for polio and pentavalent (containing diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenza type b antigens) type b antigens) vaccines, and at 9 months for measles vaccine. Participants in incentive arms will, in addition to text message reminders as above, receive mobile phone–based incentives after each timely vaccination, where timely is defined as vaccination within 2 weeks of the scheduled date for each of the four routine expanded program immunization (EPI) vaccination visits. Mother-infant pairs will be followed to 12 months of age where the primary outcome, a fully immunized child, will be ascertained. A fully immunized child is defined as a child receiving vaccines for bacille Calmette-Guerin, three doses of pentavalent and polio, and measles by 12 months of age. General estimating equation (GEE) models that account for clustering will be employed for primary outcome analyses.

Results

Enrollment was completed in October 2014. Twelve month follow-up visits to ascertain immunization status from the maternal and child health booklet were completed in February 2016.

Conclusions

This is one of the first studies to examine the effect of text message reminders on immunization coverage and timeliness in a lower income country and is the first study to assess the effect of mobile money-based incentives to improve immunization coverage.

Trial Registration

Clinicaltrials.gov NCT01878435; https://clinicaltrials.gov/ct2/show/NCT01878435 (Archived by WebCite at http://www.webcitation.org/6hQlwGYJR)

Factors Affecting Timeliness of Immunization Coverage Among Children of Assam, India

This article attempts to estimate timeliness of vaccination coverage and to model the pattern of timeliness of vaccination using techniques of survival analysis in order to trace the determinants of age-appropriate immunization status of children. Multistage cluster sampling has been used to collect information on immunization and other related variables using a pre-tested questionnaire from the universe of children of age between 12 and 36 months of two districts of Assam, India. At first, the Kaplan–Meier product limit estimator has been applied to estimate the age-appropriate immunization coverage. Though the immunization coverage as a whole is quite satisfactory in the study area, the Kaplan–Meier estimator shows poor age-appropriate immunization coverage which necessitates studying the impact of different demographic and socio-economic factors on this problem. In this context, the Cox proportional hazard model has been used which is found to be a good fit. The findings of this model show that education of mother, caste, religion and socio-economic status of the family have significant impact on the age-appropriate immunization coverage of children. Thus, it can be concluded that though the child immunization coverage in Assam has been inclining, there is still a lot of concern over the timeliness of vaccination coverage.

Immunization coverage and predictive factors for complete and age-appropriate vaccination among preschoolers in Athens, Greece: a cross--sectional study

BACKGROUND

In Greece, several new childhood vaccines were introduced recently but were reimbursed gradually and at different time points. The aim of this study was to assess immunization coverage and identify factors influencing complete and age-appropriate vaccination among children attending public nurseries in the municipal district of Athens.

METHODS

A cross-sectional study, using stratified sampling was performed. Immunization history was obtained from vaccination booklets. Demographic and socioeconomic data were obtained from school registries and telephone interviews. Vaccination rates were estimated by sample weighted proportions while associations between complete and age-appropriate immunization and potential determinants by logistic regression analysis.

RESULTS

A total of 731 children (mean age: 46, median: 48, range: 10-65 months) were included. Overall immunization coverage with traditional vaccines (DTP, polio, Hib, HBV, 1st dose MMR) was satisfactory, exceeding 90%, but the administration of booster doses was delayed (range: 33.7- 97.4%, at 60 months of age). Complete vaccination rates were lower for new vaccines (Men C, PCV7, varicella, hepatitis A), ranging between 61-92%. In addition, a significant delay in timely administration of Men C, PCV7, as well as HBV was noted (22.9%, 16.0% and 27.7% at 12 months of age, respectively). Child's age was strongly associated with incomplete vaccination with all vaccines (p< 0.001), while as immigrant status was a predictor of incomplete (p=0.034) and delayed vaccination (p<0.001) with traditional vaccines. Increasing household size and higher maternal education were negatively associated with the receipt of all and newly licensed vaccines, respectively (p=0.035).

CONCLUSIONS

Our findings highlight the need to monitor uptake of new vaccines and improve age- appropriate administration of booster doses as well as early vaccination against hepatitis B. Immigrant status, increased household size and high maternal education may warrant targeted intervention.

The pertussis epidemic: informing strategies for prevention of severe disease

To assess the impact of Bordetella pertussis infections in South Australia during an epidemic and determine vulnerable populations, data from notification reports for pertussis cases occurring between July 2008 and December 2009 were reviewed to determine the distribution of disease according to specific risk factors and examine associations with hospitalizations. Although the majority (66%) of the 6230 notifications for pertussis occurred in adults aged >24 years, the highest notification and hospitalization rate occurred in infants aged <1 year. For these infants, factors associated with hospitalization included being aged <2 months [relative risk (RR) 2·3, 95% confidence interval (CI) 1·60-3·32], Indigenous ethnicity (RR 1·7, 95% CI 1·03-2·83) and receiving fewer than two doses of pertussis vaccine (RR 4·1, 95% CI 1·37-12·11). A combination of strategies aimed at improving direct protection for newborns, vaccination for the elderly, and reducing transmission from close contacts of infants are required for prevention of severe pertussis disease.

Vaccination coverage and timeliness in three South African areas: a prospective study

BACKGROUND

Timely vaccination is important to induce adequate protective immunity. We measured vaccination timeliness and vaccination coverage in three geographical areas in South Africa.

METHODS

This study used vaccination information from a community-based cluster-randomized trial promoting exclusive breastfeeding in three South African sites (Paarl in the Western Cape Province, and Umlazi and Rietvlei in KwaZulu-Natal) between 2006 and 2008. Five interview visits were carried out between birth and up to 2 years of age (median follow-up time 18 months), and 1137 children were included in the analysis. We used Kaplan-Meier time-to-event analysis to describe vaccination coverage and timeliness in line with the Expanded Program on Immunization for the first eight vaccines. This included Bacillus Calmette-Guérin (BCG), four oral polio vaccines and 3 doses of the pentavalent vaccine which protects against diphtheria, pertussis, tetanus, hepatitis B and Haemophilus influenzae type B.

RESULTS

The proportion receiving all these eight recommended vaccines were 94% in Paarl (95% confidence interval [CI] 91-96), 62% in Rietvlei (95%CI 54-68) and 88% in Umlazi (95%CI 84-91). Slightly fewer children received all vaccines within the recommended time periods. The situation was worst for the last pentavalent- and oral polio vaccines. The hazard ratio for incomplete vaccination was 7.2 (95%CI 4.7-11) for Rietvlei compared to Paarl.

CONCLUSIONS

There were large differences between the different South African sites in terms of vaccination coverage and timeliness, with the poorer areas of Rietvlei performing worse than the better-off areas in Paarl. The vaccination coverage was lower for the vaccines given at an older age. There is a need for continued efforts to improve vaccination coverage and timeliness, in particular in rural areas.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov: NCT00397150.

Is vaccination coverage a good indicator of age-appropriate vaccination? A prospective study from Uganda

BACKGROUND

Timely vaccination is important to protect children from common infectious diseases. We assessed vaccination timeliness and vaccination coverage as well as coverage of vitamin A supplementation in a Ugandan setting.

METHODS AND FINDINGS

This study used vaccination information gathered during a cluster-randomized trial promoting exclusive breastfeeding in Eastern Uganda between 2006 and 2008 (ClinicalTrials.gov no. NCT00397150). Five visits were carried out from birth up to 2 years of age (median follow-up time 1.5 years), and 765 children were included in the analysis. We used Kaplan-Meier time-to-event analysis to describe vaccination coverage and timeliness. Vaccination coverage at the end of follow-up was above 90% for all vaccines assessed individually that were part of the Expanded Program on Immunization (EPI), except for the measles vaccine which had 80% coverage (95%CI 76-83). In total, 75% (95%CI 71-79) had received all the recommended vaccines at the end of follow-up. Timely vaccination according to the recommendations of the Ugandan EPI was less common, ranging from 56% for the measles vaccine (95%CI 54-57) to 89% for the Bacillus Calmette-Guérin (BCG) vaccine (95%CI 86-91). Only 18% of the children received all vaccines within the recommended time ranges (95%CI 15-22). The children of mothers with higher education had more timely vaccination. The coverage for vitamin A supplementation at end of follow-up was 84% (95%CI 81-87).

CONCLUSIONS

Vaccination coverage was reasonably high, but often not timely. Many children were unprotected for several months despite being vaccinated at the end of follow-up. There is a need for continued efforts to optimise vaccination timeliness.