Monitoring of timely and delayed vaccinations: a nation-wide registry-based study of Norwegian children aged < 2 years

Racial inequalities in child vaccination and barriers to vaccination in Brazil among live births in 2017 and 2018: an analysis of a retrospective cohort of the first two years of life

OBJECTIVE

To describe timely vaccination completion and obstacles in the first 24 months of life in Brazil, examining associations with maternal race/skin color.

METHODS

Study participants were 37,801 children born in 2017 and 2018 included in the National Immunization Coverage Survey. We calculated prevalence and 95% confidence intervals for timely vaccine completeness and obstacles at 5, 12 and 24 months of life, according to maternal race/skin color. Associations were analyzed using logistic regression.

RESULTS

7.2% (95%CI 6.3;8.2) of mothers faced difficulties in taking their children to be vaccinated, and 23.4% (95%CI 21.7;25.1) were not vaccinated when taken. These proportions were 75% (95%CI 1.25;2.45) and 97% (95%CI 1.57;2.48) higher, respectively, among Black mothers. At least one vaccination was delayed among 49.9% (95%CI 47.8;51.9) and 61.1% (95%CI 59.2;63.0) of children by 5 and 12 months, respectively. These rates were higher among Black/mixed race mothers.

CONCLUSION

There are racial inequalities in both the obstacles faced and in vaccination rates in Brazil.

MAIN RESULTS

Marked racial inequalities were found in the obstacles to vaccination of children under 24 months in Brazil and to timely vaccination at 5 months and in the first year of life.

IMPLICATIONS FOR SERVICES

Racial inequalities in the occurrence of vaccination shortcomings in health services, in the objective restrictions faced by families in taking their children to vaccination centers and in incomplete vaccination in a timely manner need to be addressed by the Brazilian National Health System.

PERSPECTIVES

Equal public policies to address barriers to vaccination and qualification of health services need to be implemented. Studies need to deepen understanding of the structural determinants that lead to racial disparities.

Exploring influential factors in childhood vaccine delays in Riyadh, Saudi Arabia

Introduction

Infectious diseases present a substantial worldwide health challenge, yet vaccines have played a crucial role in significantly decreasing illness rates. Despite their effectiveness, global vaccination coverage stands at 85%, leaving a considerable number of infants without routine immunization. Our study seeks to examine the occurrence of delayed primary vaccination and the factors influencing it in Riyadh, Saudi Arabia addressing a critical void in current research.

Methodology

A cross-sectional investigation was carried out in the primary care facilities of the first health cluster in Riyadh, Saudi Arabia. Information was gathered utilizing a well-structured questionnaire, modified from a prior study. The study encompassed children aged two years and younger, accompanied by their parents who brought their vaccination cards for the visit. Non-probability convenience sampling was employed for data collection. Subsequently, the data underwent thorough cleaning in Excel (Microsoft Excel) and was subjected to analysis using IBM SPSS 29 (IBM SPSS Statistics 29).

Results

The study involved 402 participants, primarily over 12 months old, with a balanced gender distribution. Noteworthy findings indicate a 20.9% prevalence of childhood vaccine delays, with reasons such as high-grade fever (33.3%) and travel (26.2%). Significant associations were found in children aged 6-12 months (25.8%, P = 0.039), families with over four children (31%, P = 0.010), perceptions of vaccine harm (50.0%, P = 0.013), and acknowledgment of neglect (96.4%, P = 0.001).

Conclusion

The research illuminates the complex factors influencing childhood vaccine delays in Saudi Arabia. Stressing the significance of personalized interventions, it underscores the necessity to tackle challenges specific to age, parental perspectives, and access issues for improved vaccination outcomes.

Childhood vaccination among Polish immigrants in Norway: a qualitative study

BACKGROUND

Confidence in childhood vaccination is high in Norway and the Norwegian Childhood Immunization Programme (NCIP) achieves high overall coverage rates. However, lower coverage has been observed for some immigrant groups, including Polish immigrants who represent the largest immigrant group in Norway. Anti-vaccine sentiments and increased refusal of mandatory childhood vaccination has been on the rise in Poland, but it is unknown whether such attitudes also apply to Polish immigrants in Norway, as they experience a different vaccination policy and perhaps also different attitudes to vaccines. This qualitative study aims to explore attitudes towards childhood vaccination in Norway among Polish immigrants.

METHODS

We interviewed 15 Polish parents living in Norway in 2022. We recruited the participants by purposive sampling and analyzed the interviews by reflexive thematic analysis.

RESULTS

Three themes were identified: views of childhood vaccination, vaccine hesitancy, and differences in childhood vaccination between Poland and Norway. Overall, the participants favored childhood vaccination and viewed most of the vaccines included in the NCIP as safe and reliable. Human papilloma virus, meningococcal and pneumococcal vaccines were declined by some of the parents. Comparisons of childhood vaccination in Poland and Norway was evident in many of the interviews, especially among parents whose children had received vaccines in both countries. The participants were well acquainted with the NCIP, favored voluntary childhood vaccination, and the majority expressed a high level of trust in Norwegian health authorities.

CONCLUSIONS

Polish immigrants to Norway generally expressed positive views about childhood vaccination. Non-vaccination was related to lack of knowledge and/or unfamiliarity with certain vaccines and not with anti-vaccine sentiments or conspiracy theories. The study highlights how parents' knowledge, in combination with norms and trends from both birth country and country of residence, influence parents' decision making about vaccination.

Early identification of at-risk children: service improvement study using immunisation status

BACKGROUND

Children who have adverse childhood experiences (ACEs) tend to have more physical and mental health problems when they are adults compared with people who do not have ACEs. Evidence suggests that partial or no immunisation status can be associated with factors (including ACEs) that make children at higher risk of poor outcomes than immunised children.

AIM

To explore the idea that 'missed immunisations' could be used as a proxy indicator in identifying children at risk of worse outcomes.

DESIGN & SETTING

Service improvement study in seven GP practices in south London, UK.

METHOD

Children aged 0-3 years who were ≥3 months late for immunisations were identified; their computer notes were reviewed during interdisciplinary meetings between health visitors (HVs) and GP practice staff. A bespoke template was used to guide discussions and to record action plans. Evaluation methods included a survey of practitioners and anonymised questionnaires about care management for a sample of children.

RESULTS

Issues of concern, including some ACEs (for example, domestic abuse, mental health concerns in parent), were identified in 57% of children. Ninety-four per cent of practitioners found multidisciplinary meetings useful; 62% of practitioners changed the way they thought about providing care to very young children and their families. Of the children discussed during multidisciplinary meetings, 38% subsequently caught up on immunisations.

CONCLUSION

'Late for immunisations' appears to be a useful indicator for proactively identifying children with issues that make them at risk of poorer outcomes. Integrated working between GPs and HVs is important for ensuring targeted care is provided to families.

Cohort profile: Health trajectories of Immigrant Children (CRIAS)-a prospective cohort study in the metropolitan area of Lisbon, Portugal

PURPOSE

The CRIAS (Health trajectories of Immigrant Children in Amadora) cohort study was created to explore whether children exposed to a migratory process experience different health risks over time, including physical health, cognitive, socioemotional and behavioural challenges and different healthcare utilisation patterns.

PARTICIPANTS

The original CRIAS was set up to include 604 children born in 2015, of whom 50% were immigrants, and their parents. Recruitment of 420 children took place between June 2019 and March 2020 at age 4/5 years, with follow-up carried out at age 5/6 years, at age 6/7 years currently under way.

FINDINGS TO DATE

Baseline data at age 4/5 years (2019-2020) suggested immigrant children to be more likely to belong to families with less income, compared with non-immigrant children. Being a first-generation immigrant child increased the odds of emotional and behavioural difficulties (adjusted OR 2.2; 95% CI: 1.06 to 4.76); more immigrant children required monitoring of items in the psychomotor development test (38.5% vs 28.3%). The prevalence of primary care utilisation was slightly higher among immigrant children (78.0% vs 73.8%), yet they received less health monitoring assessments for age 4 years. Utilisation of the hospital emergency department was higher among immigrants (53.2% vs 40.6%). Age 5 years follow-up (2020-2021) confirmed more immigrant children requiring monitoring of psychomotor development, compared with non-immigrant children (33.9% vs 21.6%). Economic inequalities exacerbated by post-COVID-19 pandemic confinement with parents of immigrant children 3.2 times more likely to have their household income decreased.

FUTURE PLANS

Further follow-up will take place at 8, 10, 12/13 and 15 years of age. Funds awarded by the National Science Foundation will allow 900 more children from four other Lisbon area municipalities to be included in the cohort (cohort-sequential design).

Comparative analysis of pre-Covid19 child immunization rates across 30 European countries and identification of underlying positive societal and system influences

This study provides a macro-level societal and health system focused analysis of child vaccination rates in 30 European countries, exploring the effect of context on coverage. The importance of demography and health system attributes on health care delivery are recognized in other fields, but generally overlooked in vaccination. The analysis is based on correlating systematic data built up by the Models of Child Health Appraised (MOCHA) Project with data from international sources, so as to exploit a one-off opportunity to set the analysis within an overall integrated study of primary care services for children, and the learning opportunities of the 'natural European laboratory'. The descriptive analysis shows an overall persistent variation of coverage across vaccines with no specific vaccination having a low rate in all the EU and EEA countries. However, contrasting with this, variation between total uptake per vaccine across Europe suggests that the challenge of low rates is related to country contexts of either policy, delivery, or public perceptions. Econometric analysis aiming to explore whether some population, policy and/or health system characteristics may influence vaccination uptake provides important results-GDP per capita and the level of the population's higher education engagement are positively linked with higher vaccination coverage, whereas mandatory vaccination policy is related to lower uptake rates. The health system characteristics that have a significant positive effect are a cohesive management structure; a high nurse/doctor ratio; and use of practical care delivery reinforcements such as the home-based record and the presence of child components of e-health strategies.

Magnitude and associated factors of delayed vaccination among children aged 11-23 months in, Tigray, Ethiopia, 2018

BACKGROUND

Delay in receiving the vaccination is a major public health problem that has been associated with vaccine-preventable disease epidemics. In Ethiopia, many children have not received the benefits of age-appropriate vaccination; thus more than 90% of child deaths are largely due to preventable communicable diseases.

OBJECTIVE

The present study assessed the magnitude and associated factors of delayed vaccination among 12-23 months old children in Tigray, Ethiopia.

METHODS

A community-based cross-sectional study was carried out among 393, 12-23 months old children from July 1 to 30, 2018. Data were collected using a structured interviewer-administered questionnaire. The questionnaire includes socio-demographic, economic factors, Maternal/caregiver factors, Child's factors, and Service-related factors. We applied bivariable and multivariable logistic regression to determine predictors for delayed Vaccination. The odds ratio with 95% CI was computed to evaluate the strength of the association.

RESULTS

393 participants were involved in the study. The magnitude of delayed vaccination was 29.5% (95% CI 26.7-45). Mothers who attend tertiary (University/college) education (AOR 0.169, 95% CI 0.032-0.882), and secondary education (AOR 0.269, 95% CI 0.114-0.636) had the protective effect of delayed vaccination. But the sickness of a child (AOR = 11.8, 95% CI 6.16-22.65) was a risk for delayed vaccination.

CONCLUSIONS

The magnitude of delayed vaccination was high, particularly among participants with Mother's education, and Mother's consideration in the child's wellness to take the vaccine. This implies that it is important to give emphasis, especially for the mothers who have an uneducated and sick child to increase awareness about the advantage of vaccination, which will improve on-time vaccination.

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.

Timeliness of Childhood Vaccination Coverage: the Growing Up in Singapore Towards Healthy Outcomes Study

Studies investigating timeliness for childhood vaccination are limited especially in Asia. We examined the timeliness of vaccine administration and associated factors among infant and young children in Singapore. A total of 782 children born between November 2009 and July 2011 from a prospective cohort in Singapore were studied. Vaccination records from birth to 24 months of age were obtained from the National Immunization Registry of Singapore. Multivariable logistic regression models were performed. By 2 years of age, 92.8% of children in our cohort experienced a delay in receiving 1 or more vaccine doses according to the recommended national immunization schedule. When vaccinations were reviewed by series for each vaccine, 15.6% received all vaccine series outside the recommended age ranges. Factors associated with receiving vaccination series outside the recommended ages included maternal aged ≤ 35 years (OR 2.00; 95% CI 1.09, 3.66), Malay (1.71; 1.01, 2.89) or Indian ethnicity (2.06; 1.19, 3.59), low monthly household income (1.91; 1.14, 3.18), having at least four children (3.46; 1.62, 7.38) and private (3.42; 1.80, 6.48) and multiple vaccination providers (3.91; 1.23, 12.48). These findings show an unacceptably high proportion of children experienced a delay in the receipt of their vaccinations. The identification of several demographic, socioeconomic, health-seeking behavioural and vaccine provider factors provides opportunities for targeted interventions to enhance the timeliness of childhood vaccination in Singapore.

Impact of the Rotavirus Vaccination Program in Norway After Four Years With High Coverage

BACKGROUND

Use of rotavirus vaccines worldwide since 2006 has led to a significant impact on the burden of rotavirus disease. However, only a third of European countries have introduced rotavirus vaccination in their immunization programs. In October 2014, rotavirus vaccination was introduced for Norwegian infants under strict age restrictions. Exclusive use of the monovalent rotavirus vaccine (RV1) and high vaccination coverage from the beginning enabled evaluation of the impact of this vaccine during the first 4 years after introduction.

METHODS

Prospective laboratory-based surveillance among children <5 years of age hospitalized for acute gastroenteritis at 5 Norwegian hospitals was used to assess the vaccine effectiveness of 2 vaccine doses against rotavirus hospitalization in a case-control study. We used community controls selected from the national population-based immunization registry, and test-negative controls recruited through hospital surveillance. We also assessed the vaccine impact by using time-series analysis of retrospectively collected registry data on acute gastroenteritis in primary and hospital care during 2009-2018.

RESULTS

Vaccine effectiveness against rotavirus-confirmed hospitalization was 76% (95% confidence interval [CI]: 34%-91%) using test-negative controls, and 75% (95% CI: 44%-88%) using community controls. In the postvaccine period, acute gastroenteritis hospitalizations in children <5 years were reduced by 45% compared with the prevaccine years (adjusted incidence rate ratios 0.55; 95% CI: 0.49-0.61). Reduction in hospitalizations was also seen in cohorts not eligible for vaccination. Rates in primary care decreased to a lesser degree.

CONCLUSIONS

Four years after introduction of rotavirus vaccination in the national childhood immunization program, we recorded a substantial reduction in the number of children hospitalized for acute gastroenteritis in Norway, attributable to a high vaccine effectiveness.

Vaccine coverage in children born to migrant mothers in Australia: A population-based cohort study

BACKGROUND

Overall, infant immunisation coverage is currently >90% in Australia, but there are pockets of under-immunised children including children from migrant backgrounds. This study aimed to examine whether on-time vaccination coverage of diphtheria-tetanus-pertussis dose 3 (DTP3) for children born in Australia differed by mother's region of birth and if so, what factors were associated with these differences.

METHODS

We conducted a population-based cohort study using linked data on perinatal, immunisation and birth records for 2 million children born in Western Australia and New South Wales between 1996 and 2012. We assessed on-time coverage of DTP3 (vaccination from 2 weeks prior to, and up until 30 days after, the due date) in children with mothers born overseas. Logistic regression models were developed to determine factors associated with on-time coverage for each maternal region of birth and all regions combined, adjusting for a range of demographic factors. Adjusted estimates of coverage were calculated for the different regions of birth.

RESULTS

On-time DTP3 coverage was 76.2% in children of Australian born mothers, lower in children of mothers from Oceania (66.7%) and North America (68%), and higher in children born to mothers from South-East Asia (79.9%) and Southern Asia (79.3%). While most variables were consistently associated with lower coverage in all regions of birth, higher socioeconomic status and jurisdiction of birth showed varied results. Adjusted estimates of DTP3 coverage increased in children born to mothers from Australia (78.3%), Oceania (70.5%), Northern Africa (81.5%) and the Middle East (79.6%). DTP3 coverage decreased in children born to mothers from Europe and former USSR (74.6%), North-east Asia (75.2%), Southern Asia (76.7%), North America (65.5) and South/Central America and the Caribbean (73.2%).

CONCLUSIONS

On-time vaccination rates differed by mother's region of birth. More research is needed to determine the main reasons for these remaining differences to improve vaccine uptake and also help guide policy and practice.

Trends in pediatric hospitalizations for ambulatory care sensitive respiratory diseases in Brazil

OBJECTIVE

To analyze the trend in hospitalization rates for ambulatory care sensitive respiratory diseases (ACSRD) of children under five years of age in Brazil.

DESIGN

Time series study of hospitalization rates using secondary information from the Hospital Information System of the Brazil's Unified Health System.

SAMPLE

Hospitalizations of children under five years of age living in Brazilian regions. Hospitalizations were separated according to cause: nose and throat infections, asthma, bacterial pneumonias, and lung diseases.

MEASUREMENTS

Rates were calculated for total hospitalizations for ACSRD, and by cause, age group, and region. Trends were analyzed by using means of simple linear regression and were classified into stationary (p ≥ .05), ascending (β positive and p < .05) or declining (β negative and p < .05) trends.

RESULTS

All regions showed stationary trends in total hospitalization rates for ACSRDs, except in the Southeast, where trends were ascending. Asthma was the only cause that showed a declining trend. Bacterial pneumonias showed stationary trends, while lung diseases and nose and throat infections had predominantly ascending trends.

CONCLUSION

Brazil's hospitalization rates for ACSRDs are high. Investigations into primary health care organization and work processes, as well as socioeconomic, cultural, and geographical factors are necessary.

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.

Serotype evolution in Western Europe: perspectives on invasive pneumococcal diseases (IPD)

Introduction: Epidemiologic trends for IPD have evolved with the introduction of pneumococcal conjugate vaccines into childhood immunization programs. We document the ongoing impact of PCV programs in 15 Western European countries.Areas covered: Data were collected from relevant published observational studies and national surveillance websites from January 2010 through January 2018. In countries using PCV13, the proportion of IPD due to PCV13 serotypes declined significantly (from 60-78% to 8-26%) in children <5 years of age within 5-8 years following vaccine introduction. In countries using PCV10, a marked decrease in PCV10-serotype IPD was reported; however, the proportion of IPD due to PCV13 serotypes remained high at 58-64%, predominantly due to serotypes 19A and 3.Expert opinion: The prevalence of vaccine-type IPD in adults remained high; emerging non-vaccine serotypes such as 8, 12F, 22F, 33F, and 15B/C should be a focus of future vaccine development.

ADVANCE system testing: Can coverage of pertussis vaccination be estimated in European countries using electronic healthcare databases: An example

INTRODUCTION

The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines, using existing healthcare databases in Europe. The objective of this paper was to assess the feasibility of using electronic healthcare databases to estimate dose-specific acellular pertussis (aP) and whole cell pertussis (wP) vaccine coverage.

METHODS

Seven electronic healthcare databases in four European countries (Denmark (n = 2), UK (n = 2), Spain (n = 2) and Italy (n = 1)) participated in this study. Children were included from birth and followed up to age six years. Vaccination exposure was obtained from the databases and classified by type (aP or wP), and dose 1, 2 or 3. Coverage was estimated using period prevalence. For the 2006 birth cohort, two estimation methods for pertussis vaccine coverage, period prevalence and cumulative incidence were compared for each database.

RESULTS

The majority of the 2,575,576 children included had been vaccinated at the country-specific recommended ages. Overall, the estimated dose 3 coverage was 88-97% in Denmark (birth cohorts from 2003 to 2014), 96-100% in the UK (2003-2014), 95-98% in Spain (2004-2014) and 94% in Italy (2006-2007). The estimated dose 3 coverage per birth cohort in Denmark and the UK differed by 1-6% compared with national estimates, with our estimates mostly higher. The estimated dose 3 coverage in Spain differed by 0-2% with no consistent over- or underestimation. In Italy, the estimates were 3% lower compared with the national estimates. Except for Italy, for which the two coverage estimation methods generated the same results, the estimated cumulative incidence coverages were consistently 1-10% lower than period prevalence estimates.

CONCLUSION

This study showed that it was possible to provide consistent estimates of pertussis immunisation coverage from the electronic healthcare databases included, and that the estimates were comparable with the national estimates.

Pertussis clinical case definition: Time for change in developing countries?

Background

Developing countries still struggle with late detection and mortality from pertussis. A review of clinical case definitions is necessary for early disease detection. This paper aimed to study possible clinical characteristics for earlier pertussis detection in a sporadic setting.

Methods

We conducted a retrospective review of medical and laboratory records in a general paediatric ward of a district hospital in a developing country. Inclusion criteria were all children hospitalised with nasopharyngeal swab taken for Bordetella pertussis. We compared sensitivity and specificity of World Health Organization diagnostic criteria with other clinical characteristics. Polymerase chain reaction Bordetella pertussis was the gold standard used.

Results

Out of 207 eligible admissions, the study retrieved 128 complete records. Approximately half of the children were less than 3 months old. The World Health Organization diagnostic criteria had a low sensitivity (15%), but high specificity (92%). In comparison, combinations that included paroxysmal cough, ill contact and facial congestion had higher sensitivity. Increasing cough duration improved specificity while compromising sensitivity.

Conclusion

Several clinical characteristics such as paroxysmal cough, facial congestion and a history of ill contact have potential for early clinical detection. Conventional emphasis on cough duration may hamper early detection.

Countering vaccine hesitancy through immunization information systems, a narrative review

Immunization is one of the most important public health interventions to contrast infectious disease; however, many people nowadays refuse vaccination. Vaccine hesitancy (VH) is due to several factors that influence the complex decision-making process. Information technology tools might play an important role in vaccination programs. In particular, immunization information systems (IISs) have the potential to improve performance of vaccination programs and to increase vaccine uptake. This review aimed to present IIS functionalities in order to counter VH. In detail, we analyzed the automatic reminder/recall system, the interoperability of the system, the decision support system, the web page interface and the possibility to record adverse events following immunization. IIS could concretely represent a valid instrument to increase vaccine confidence, especially trust in both health-care workers and decision makers. There are not enough trials aimed to evaluate the efficacy of IIS to counter VH. Further researches might focalize on this aspect.

Are we speaking the same language? an argument for the consistent use of terminology and definitions for childhood vaccination indicators

Vaccination indicators are used to measure the health status of individuals or populations and to evaluate the effectiveness of vaccination programs or policies. Ensuring that vaccination indicators are clearly and consistently defined is important for effective communication of outcomes, accurate program evaluation, and comparison between different populations, times, and contexts. The purpose of this commentary is to describe commonly used vaccination indicators and to highlight inconsistencies in how childhood vaccine researchers use and define these terms. The indicators we describe are vaccine coverage, uptake, and rate; vaccination status, initiation, and completion; and up-to-date, timely, partial, and incomplete vaccination. We conclude that many vaccination indicators are not explicitly defined within published research studies and/or are used quite differently across studies. We also note that the choice of indicator in a given study is often driven by program or vaccine specific factors, may be constrained by data availability, and should be chosen to best reflect the outcome of interest. We conclude that the use of consistent language and definitions would promote more effective communication of research findings. We also propose some standardized definitions for common indicators, with the goal of provoking discussion and debate on the issue.

How are children who are delayed in the Childhood Vaccination Programme vaccinated: A nationwide register-based cohort study of Danish children aged 15-24 months and semi-structured interviews with vaccination providers

Aims: Delay of childhood vaccinations is common and influences efforts to reduce targeted diseases. In Denmark, the diphtheria, tetanus, pertussis, polio and Haemophilus influenzae type b (DTaP-IPV-Hib) vaccine is recommended at ages 3, 5 and 12 months and the first measles-mumps-rubella vaccine (MMR-1) at 15 months. Following guidelines, children delayed at age 15 months should receive MMR-1 and DTaP-IPV-Hib-3 simultaneously, unless DTaP-IPV-Hib-2 was received less than 6 months ago, when MMR-1 alone is recommended. We studied compliance with these guidelines and the reasons for non-compliance with a focus on vaccination providers. Methods: We used a nationwide register-based cohort study of children born in Denmark between January 2000 and June 2013, who were lacking MMR-1 and DTaP-IPV-Hib-3 at age 15 months and were followed to 24 months. We also performed semi-structured telephone interviews with vaccination providers. Results: The study consisted of 156,921 children (18% of the children born in the period). Among the 40,060 children who had received DTaP-IPV-Hib-2 less than 6 months ago, 37,892 (95%) received MMR-1 alone. Among the 88,469 children who had received DTaP-IPV-Hib-2 more than 6 months ago, 6334 (7%) received DTaP-IPV-Hib-3 and MMR-1 simultaneously. The interviews indicated that some vaccination providers are reluctant to give multiple vaccinations at the same visit and some have a preference of following the usual sequence in the programme. Conclusions: Vaccination providers generally complied with the recommended minimum 6 months' interval between DTaP-IPV-Hib-2 and DTaP-IPV-Hib-3. Conversely, there was a low compliance with the recommendation to administer DTaP-IPV-Hib-3 and MMR-1 simultaneously. More efforts are needed to ensure timely vaccination.

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.

Risk of Pertussis in Relation to Degree of Prematurity in Children Less Than 2 Years of Age

BACKGROUND

A few previous studies reported increased risk of pertussis in children with birth weight less than 2500 g. The risk of pertussis by degree of prematurity has not been determined in a cohort study. The vaccine effectiveness (VE) against reported pertussis in preterm infants is unknown.

METHODS

Data were obtained from the Medical Birth Registry of Norway (1998-2010) and linked to other national registries. In total, 713,166 children were included in our study and followed until 2 years of age. Incidence rate ratios (IRRs) and confidence intervals (CIs) were estimated with Poisson regression.

RESULTS

We identified 999 reported cases of pertussis. We observed a higher rate of reported pertussis in preterm than in full-term infants, IRR = 1.65 (95% CI: 1.32-2.07). Compared to full-term infants, the risk of reported pertussis in infants born at gestational age (GA) 35-36, 32-34 and 23-27 weeks were higher [IRRs = 1.49 (95% CI: 1.11-2.01), 1.63 (95% CI: 1.06-2.51) and 4.49 (95% CI: 2.33-8.67), respectively]. Moreover, preterm infants had a higher rate of pertussis-related hospitalization than full-term infants [IRR = 1.99 (95% CI: 1.47-2.71)]. The VE against reported pertussis for the third dose was 88.8% (95% CI: 84.3-92.0) in full-term infants and 93.0% (95% CI: 85.8-96.5) in preterm infants.

CONCLUSIONS

In this cohort study, preterm infants including those born at GA 35 and 36 weeks had increased risk of reported pertussis. The VE was similar in preterm and full-term infants.