BCG coverage and barriers to BCG vaccination in Guinea-Bissau: an observational study

Implementation of the vaccination program in Guinea-Bissau: Coverage and missed opportunities for BCG at birth

BACKGROUND

The Bacillus Calmette-Guérin (BCG) vaccine is recommended at birth in Guinea-Bissau but often given with delay. Delays are not evident in routine coverage estimates since coverage is measured by 12 months of age. Studies show that BCG protects against other infections than tuberculosis and lowers neonatal mortality. Hence, the timing of BCG is important since the children should benefit from these non-specific effects as early as possible.

METHODS

Using data from a nationally representative health and demographic surveillance system in Guinea-Bissau, we assessed BCG coverage at birth (within the first 3 days of life), 1 month, and 12 months for children born in 2013-19. We measured the proportion of children who had a documented health system contact within the first 3 days of life, thus an opportunity for BCG at birth, and whether the opportunities were utilized. In binomial regression models, we investigated factors associated with missed opportunities for vaccination.

RESULTS

Among the 22,178 children only 19 % were vaccinated at birth. By 1 month and 12 months, BCG coverages were 64 % and 93 %. The timeliness of BCG improved over time, with coverage at birth increasing from 16 % in 2013 to 25 % in 2019 and 1-month coverage from 63 % in 2013 to 75 % in 2019. If all vaccination opportunities had been utilized, the BCG coverage at birth could have reached 45 % (in the 1-month cohort) instead of the actual coverage of 19 %, as only 40 % of the vaccination opportunities were utilized. Region of residence was associated with having a missed opportunity for vaccination.

CONCLUSION

The high coverage estimates at 12 months falsely imply that the vaccine is being administered according to the recommended schedule. Our findings suggest that early coverage could be markedly improved by ensuring that children are vaccinated at their first contact with the health system.

Coverage of BCG Vaccination for children aged until 7 years old and its determinants in French Guiana

INTRODUCTION

The overall incidence of tuberculosis (TB) in France is low; thus, BCG vaccination is no longer mandatory. In French Guiana - a French overseas territory - BCG vaccination is strongly recommended because the incidence of TB is high in the context of mass immigration from endemic countries with low BCG vaccination rates. Thus, it is important to assess Bacillus Calmette-Guérin (BCG) vaccination coverage and its predictors.

METHODS

We used data from the 2014 French Guiana Yellow Fever survey, which was conducted by the Observatoire Régional de la Santé de Guyane. Demographic and immunization data from eligible children and their families were collected using a questionnaire. Children who had an immunization card and who were no older than 7 years of age at the time of the survey were eligible. The Coverage for BCG and other mandatory vaccines were estimated; the delay in BCG vaccination was also computed. Univariate and multivariate analyses identified predictors associated with BCG immunization and BCG delayed immunization (after 2 months of age).

RESULTS AND CONCLUSION

Overall, 469 children were eligible for this study. The total BCG coverage was 79.5 %, and the proportion of children vaccinated with delay was 50.7 %. The multivariate analysis indicated that BCVA was significantly greater among children younger than 3 years of age, whose household head was employed and whose education level was greater. None of the predictors were associated with the delay of BCG vaccination.

Can earlier BCG-Japan and OPV vaccination reduce early infant mortality? A cluster-randomised trial in Guinea-Bissau

OBJECTIVE

To assess the effect of providing BCG and oral polio vaccine (OPV) at an early home visit after delivery.

DESIGN

Cluster-randomised trial, randomising 92 geographically defined clusters 1:1 to intervention/control arms.

SETTING

Bandim Health Project Health and Demographic Surveillance System, Guinea-Bissau.

PARTICIPANTS

2226 newborns enrolled between July 2016 and August 2019.

INTERVENTIONS

In both arms, newborns received a home visit within 72 hours after birth. In intervention clusters (n=46), BCG and OPV were provided at the home visit.

MAIN OUTCOME MEASURE

Rates of non-accidental mortality were compared in Cox proportional hazards models from (last of) day 1 or enrolment, until (first of) day 60 or registration of non-trial vaccines.

RESULTS

A total of 35 deaths (intervention: 7, control: 28) were registered during the trial. Providing BCG and OPV reduced non-accidental early infant mortality by 59% (8-82%). The intervention also reduced non-accidental hospital admissions. The intervention had little impact on growth and BCG scarring and tended to increase the risk of consultations.

CONCLUSIONS

The trial was stopped early due to lower-than-expected enrolment and event rates when 33% of the planned number of newborns had been enrolled. Despite the small size of the trial, the results support that early BCG and OPV vaccinations are beneficial and reduce early child mortality and morbidity.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT02504203).

Can BCG vaccination at first health-facility contact reduce early infant mortality? Study protocol for a cluster-randomised trial (CS-BCG)

INTRODUCTION

Increasing evidence suggests that the BCG vaccine has non-specific effects, altering the susceptibility to non-tuberculous infections. Thus, early BCG vaccination may reduce mortality. BCG is recommended at birth but is often delayed. Vaccination opportunities are missed due to multidose vials not being opened for a few children. We will assess the effect of making BCG available at the first health-facility contact on early infant mortality and morbidity in a rural setting in Guinea-Bissau.

METHODS AND ANALYSIS

In a cluster-randomised crossover trial, we randomise 23 health centres to two different treatment groups. In half of the health centres, BCG is provided as per current practice; in the remaining health centres, we make BCG available everyday to allow opening a vial of BCG if there is just one eligible child present. The randomisation of centres will be crossed over after 12 months and enrolment will continue for another 12 months.We will use logistic regression models with adjustment for village to assess the effect of making BCG available at the first health-facility contact. The main outcome is non-accidental mortality between day 1 and day 42 after birth. We will adjust for sex, health centre, period (before/after crossover) and level of surveillance (level 1 or level 2). Further analyses include assessment of the effect on hospital admission and a cost-effectiveness evaluation.

ETHICS AND DISSEMINATION

If BCG vaccination reduces early infant mortality, missed opportunities and delays of vaccinations expose infants in several low-income countries to unnecessary excess mortality risk. The present trial will provide information on the effect of implementing a feasible intervention, where all children receive BCG at their first health-facility contact. Consent is obtained from all pregnant women registered as part of the trial. The results of the study will be published and communicated to the National Institute of Public Health in Guinea-Bissau.

TRIAL REGISTRATION NUMBER

NCT04658680; Clinicaltrials.gov.

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.

Reasons given for non-vaccination and under-vaccination of children and adolescents in sub-Saharan Africa: A systematic review

To achieve the full benefits of vaccination, it is key to understand the underlying causes of low vaccination by researching the barriers to vaccination at a local level. This systematic literature review aims to identify the reasons given by community members for the non-vaccination and under-vaccination of children and adolescents in sub-Saharan Africa. PubMed, Web of Science, PsycINFO, African Index Medicus, and African Journals Online databases were searched to identify articles published between 2010 and 2020. A total of 37 articles were included. As 17 studies did not report the reasons for non-vaccination and under-vaccination separately, we considered these two outcomes as “incomplete vaccination”. The most common reasons for incomplete vaccination were related to caregiver’s time constraints, lack of knowledge regarding vaccination, the unavailability of vaccines/personnel in healthcare facilities, missed opportunities for vaccination, caregiver’s fear of minor side effects, poor access to vaccination services, and caregiver’s vaccination beliefs.

Impact of COVID-19 Disruptions on Global BCG Coverage and Paediatric TB Mortality: A Modelling Study

The impact of COVID-19 disruptions on global Bacillus Calmette-Guérin (BCG) coverage and paediatric tuberculosis (TB) mortality is still unknown. To fill this evidence-gap and guide mitigation measures, we estimated the impact of COVID-19 disruptions on global BCG coverage and paediatric TB mortality. First, we used data from multiple sources to estimate COVID-19-disrupted BCG vaccination coverage. Second, using a static mathematical model, we estimated the number of additional paediatric TB deaths in the first 15 years of life due to delayed/missed vaccinations in 14 scenarios-varying in duration of disruption, and magnitude and timing of catch-up. We estimated a 25% reduction in global BCG coverage within the disruption period. The best-case scenario (3-month disruption, 100% catch-up within 3 months) resulted in an additional 886 (0.5%) paediatric TB deaths, and the worst-case scenario (6-month disruption with no catch-up) resulted in an additional 33,074 (17%) deaths. The magnitude of catch-up was found to be the most influential variable in minimising excess paediatric TB mortality. Our results show that ensuring catch-up vaccination of missed children is a critical priority, and delivery of BCG alongside other routine vaccines may be a feasible way to achieve catch-up. Urgent action is required to support countries with recovering vaccination coverages to minimise paediatric deaths.

Vaccine Hesitancy and Refusal: Behavioral Evidence from Rural Northern Nigeria

It is widely believed that vaccine hesitancy is prevalent in African countries, although this belief is without rigorous evidence. Our field experiment in rural northern Nigeria behaviorally measured the prevalence of vaccine hesitancy-the non-uptake of vaccines despite their availability due to non-monetary factors directly associated with vaccination. We randomly assigned two tasks to women: answering a short survey at their house vs. additionally receiving a free tetanus vaccine by submitting a voucher. The differences in their completion rates captured vaccine hesitancy, showing the rate to be about 13%. Our study reveals that absolute refusers with negative willingness to pay (WTP) for vaccines, who are likely to have strong misperceptions or a distrust of vaccines, account for about half of vaccine hesitaters, while floating refusers with zero or weakly positive WTP, who are likely to be indifferent about vaccines, account for the other half. A simple intervention, such as a door-to-door vaccination campaign, is likely to be effective for floating refusers, while interventions for absolute refusers need to effectively change their misperceptions or distrust of vaccines.

Disregarding the restrictive vial-opening policy for BCG vaccine in Guinea-Bissau: impact and cost-effectiveness for tuberculosis mortality and all-cause mortality in children aged 0-4 years

Objective

BCG vaccination is frequently delayed in low-income countries. Restrictive vial-opening policies, where a vial of BCG vaccine is not opened for few children, are a major reason for delay. During delays, children are unprotected against tuberculosis (TB) and deprived of non-specific effects of BCG. We assessed the potential effect and cost-effectiveness of disregarding the restrictive vial-opening policy, on TB and all-cause mortality, in children aged 0–4 years in Guinea-Bissau.

Methods

Using static mathematical models, we estimated the absolute and percentage change in TB and all-cause deaths, in children aged 0–4 years, between the current BCG vaccine restrictive-opening policy scenario, and a non-restrictive policy scenario where all children were vaccinated in the first health-facility contact. Incremental cost-effectiveness was estimated by integration of vaccine and treatment costs.

Findings

Disregarding the restrictive BCG vial-opening policy was estimated to reduce TB deaths by 11.0% (95% uncertainty range (UR):0.5%–28.8%), corresponding to 4 (UR:0–15) TB deaths averted per birth cohort in Guinea-Bissau, resulting in incremental cost-effectiveness of US$ 911 per discounted life-year gained (LYG) (UR:145–9142). For all-cause deaths, the estimated reduction was 8.1% (UR: 3.3%–12.7%) corresponding to 392 (UR:158–624) fewer all-cause deaths and an incremental cost-effectiveness of US$ 9 (UR:5–23) per discounted LYG.

Conclusions

Disregarding the restrictive BCG vial-opening policy was associated with reductions in TB deaths and all-cause deaths and low cost-effectiveness ratios. Our results suggest that it would be cost-effective to disregard the restrictive vial-opening policy. Other settings with similar practice are also likely to gain from disregarding this policy.

Neonatal Bacille Calmette-Guérin vaccination and tuberculin skin test reactions at 2- and 6-months: Effects on mortality up to 1 year of age

BACKGROUND

In randomized trials, Bacille Calmette-Guérin (BCG) vaccine has been associated with reduced all-cause mortality. BCG-induced Tuberculin Skin Test (TST) reactions have also been associated with reduced all-cause mortality. We aimed to assess the association between TST responses and subsequent mortality in three birth cohorts and conducted a meta-analysis of existing studies.

METHODS

Observational study within three Guinea-Bissau BCG trial birth cohorts (conducted 2002-04, 2009-2013 and 2014-18) that encompassed children who were BCG-vaccinated within 28 days with TSTs performed at 2- (n = 1389) and 6-months (n = 2635) of age. We evaluated TST reaction determinants by binomial regression and assessed the association between TSTs > 1 mm (reactors) vs. ≤ 1 mm (non-reactors) and subsequent mortality risk up to age 12 months in Cox-models providing Mortality Rate Ratios (MRRs). We searched PubMed for studies to calculate meta-estimates of the association between TST reactivity by age 2- and 6-months and all-cause mortality.

RESULTS

Large post-vaccination wheal size was associated with 6-month TST positivity and so was receiving BCG-Denmark or BCG-Japan, compared with BCG-Russia. By age 2 months, 22% (302/1389) of infants were TST reactors with a 2-12-month mortality risk of 1.7% (5/302) vs. 3.3% (36/1087) for non-reactors, the corresponding reactor/non-reactor MRR = 0.49 (0.19-1.26). By age 6 months, 44% (1149/2635) of infants were reactors and the 6-12-month mortality risk was 0.4% (4/1149) vs. 0.6% (9/1486) for non-reactors, the MRR = 0.87 (0.27-2.86). The literature search provided 3 studies. The meta-analysis revealed a uniform pattern of reduced mortality associated with TST reactivity, a TST response by 2 months being associated with an MRR of 0.59 (0.39-0.90); for 6-month TST responses the MRR was 0.65 (0.43-1.00).

CONCLUSION

Among BCG-vaccinated infants, TST reactions were associated with markedly reduced mortality. Improved vaccination technique and using certain BCG strains could lead to a higher TST reaction prevalence, which would enhance BCG's beneficial non-specific effects.

BCG skin reactions by 2 months of age are associated with better survival in infancy: a prospective observational study from Guinea-Bissau

Introduction

Receiving Bacille Calmette-Guérin (BCG)-Denmark vaccine at birth has been associated with ~40% reductions in all-cause neonatal mortality. We evaluated determinants of BCG skin reaction characteristics by age 2 months and tested the association with subsequent mortality.

Methods

Prospective observational study amalgamating five trials providing BCG-at-birth that were conducted between 2002 and 2018 in Guinea-Bissau. The reaction status and size were evaluated at home-visits by 2 months of age among 6012 neonates; mortality from 2 to 12 months was assessed at subsequent visits. Reaction determinants were evaluated by binomial regression providing risk ratios (RRs). In Cox-models providing adjusted mortality rate ratios (aMRRs), we assessed the association between (1) having a 2-month reaction (yes/no) and (2) reaction size tertiles and subsequent all-cause mortality risk. A subgroup had their BCG reaction evaluated and were bled at age 4 weeks; their samples underwent in vitro analysis for specific and non-specific cytokine responses.

Results

The BCG strain was the main determinant for developing a 2-month reaction and the reaction size: the BCG-Russia/BCG-Denmark RR for large-reaction was 0.38 (0.30–0.47) and the BCG-Russia/BCG-Japan RR was 0.61 (0.51–0.72). 5804 infants (96.5%) were reactors by age 2 months; 208 (3.5%) were non-reactors. The 2–12 months mortality risk was 4.8% (10/208) for non-reactors, 2.9% (64/2213) for small reactors, 1.8% (30/1710) for medium reactors and 0.8% (15/1881) for large reactors. The reactor/non-reactor aMRR was 0.49 (0.26–0.95) and there was a linear trend of decreasing mortality with increasing reaction size (p for trend <0.001). BCG reactors had higher 4-week specific and non-specific cytokine responses, responses that were highest among those with large reactions.

Conclusion

Among BCG-vaccinated infants, having a BCG skin reaction by age 2 months was associated with markedly better survival, as was the reaction size. Our findings thus support that BCG has substantial effects on all-cause mortality. Emphasising at-birth vaccination with immunogenic BCG strains and revaccinating non-reactors and small reactors could have major public health benefits.

Trial registration numbers

NCT00146302, NCT00168610, NCT00625482, NCT01989026 and NCT02447536.

Can what have we learnt about BCG vaccination in the last 20 years help us to design a better tuberculosis vaccine?

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The BCG vaccine provides variable protection against tuberculosis.

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Correlates of protection remain elusive, but IFNγ can measure immunogenicity.

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BCG vaccination induces innate immune training as well as antigen-specific immunity.

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Many factors may contribute to the variable responses to BCG vaccination.

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Prior BCG vaccination or factors modulating its efficacy may affect new TB vaccines.

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Innate training may also provide non-specific protection against infectious diseases.

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New TB vaccines should not lose BCG's beneficial non-specific effects.

The BCG vaccine will, in 2021, have been in use for 100 years. Much remains to be understood, including the reasons for its variable efficacy against pulmonary tuberculosis in adults. This review will discuss what has been learnt about the BCG vaccine in the last two decades, and whether this new information can be exploited to improve its efficacy, by enhancing its ability to induce either antigen-specific and/or non-specific effects. Many factors affect both the immunogenicity of BCG and its protective efficacy, highlighting the challenges of working with a live vaccine in man, but new insights may enable us to exploit better what BCG can do.

BCG scarring and improved child survival: a combined analysis of studies of BCG scarring

Bacillus Calmette-Guérin (BCG) vaccine against tuberculosis (TB) is recommended at birth in TB-endemic areas. Currently, BCG vaccination programmes use "BCG vaccination coverage by 12 months of age" as the performance indicator. Previous studies suggest that BCG-vaccinated children, who develop a scar, have better overall survival compared with BCG-vaccinated children, who do not develop a scar. We summarized the available studies of BCG scarring and child survival. A structured literature search for studies with original data and analysis of BCG scarring and mortality were performed. Combined analyses on the effect of BCG scarring on overall mortality. We identified six studies covering seven cohorts, all from Guinea-Bissau, West Africa, with evaluation of BCG scarring amongst BCG-vaccinated children and follow-up for mortality. Determinants of BCG scarring were BCG strain, intradermal injection route, size of injection wheal, and co-administered vaccines and micronutrients. In a combined analysis, having a BCG scar vs. no BCG scar was associated with a mortality rate ratio (MRR) of 0.61 (95% CI: 0.51-0.74). The proportion with a BCG scar varied from 52 to 93%; the estimated effect of a BCG scar was not associated with the scar prevalence. The effect was strongest in the first (MRR = 0.48 (0.37-0.62)) and second (MRR = 0.63 (0.44-0.92)) year of life, and in children BCG-vaccinated in the neonatal period (MRR = 0.45 (0.36-0.55)). The effect was not explained by protection against TB. Confounding and genetic factors are unlikely to explain the strong association between BCG scarring and subsequent survival. Including "BCG scar prevalence" as a BCG vaccination programme performance indicator should be considered. The effect of revaccinating scar-negative children should be studied.

Coverage and Timeliness of Birth Dose Vaccination in Sub-Saharan Africa: A Systematic Review and Meta-Analysis

Background: Depending on the epidemiological context of each country, three vaccines are recommended by the World Health Organization (WHO) to be administered as soon as possible after birth (birth vaccines); namely, BCG, zero dose of oral polio vaccine (OPV0), and birth dose of hepatitis B vaccine (HepB-BD). The timely administration of these vaccines immediately after birth might pose significant challenges in sub-Saharan Africa, where about half of childbirths occur outside health facilities. We therefore conducted a systematic review and meta-analysis to estimate the coverage rate of these vaccines at a specific timing in neonates in sub-Saharan Africa. Methods: We searched PubMed, Embase, CINAHL, and Web of Science for studies conducted in sub-Saharan Africa and published up to March 31, 2017, which provided a coverage rate of the birth vaccines at any specific time points within 28 days after birth. Two investigators independently screened the titles and abstracts and extracted data from the eligible full-text articles. This study was registered in PROSPERO (CRD42017071269). Results: Of 7283 articles identified, we finally included 31 studies with 204,111 infants in the meta-analysis. The pooled coverage rates at day 0–1 after birth were 14.2% (95% CI: 10.1–18.9) for BCG and 1.3% (0.0–4.5) for HepB-BD. No data were available for OPV0 at day 0–1. The coverage at day 28 was 71.7% (63.7–79.2) for BCG, 60.8% (45.8–74.7) for HepB-BD, and 76.1% (67.1–84.0) for OPV0. No significant difference in the vaccine coverage was observed between infants born in healthcare facilities and those born outside facilities. Conclusions: The rates of vaccine coverage immediately after birth were very low for BCG and HepB-BD, and no data for OPV0. We need additional data to better define barriers and facilitators for the timely administration of the birth vaccines in sub-Saharan Africa, since the delay in its provision may increase the burden of these vaccine-preventable diseases.

Potential effect of age of BCG vaccination on global paediatric tuberculosis mortality: a modelling study

Background

BCG has been recommended at birth in countries with a high tuberculosis burden for decades, yet delayed vaccination is widespread. To support a WHO guidance review, we estimated the potential global tuberculosis mortality benefit of administering BCG on time and consequences of later administration.

Methods

We estimated age-specific BCG coverage in 152 high-burden countries using data from large, nationally representative household surveys, to parameterise a static mathematical model, calibrated to global childhood tuberculosis deaths in 2016. 12 hypothetical scenarios explored the effect of BCG delivery at birth, 6 weeks, 6 months, or 9–12 months, on tuberculosis deaths per global birth cohort by age 15 years, including delivery at the time of the first diphtheria–tetanus–pertussis vaccine (DTP1) or the first measles-containing vaccine (MCV1). We assumed constant vaccine efficacy by age, but varied coverage and degree of vaccination delay, including no delay.

Findings

In 152 high-burden countries, we estimated that BCG coverage in 2016 was 37% at 1 week of age, 67% at 6 weeks, and 92% at 3 years. Modelled scenarios in which 92% BCG coverage was achieved at birth reduced tuberculosis deaths in the global birth cohort by 5449 (95% uncertainty range 218–15 071) or 2·8% (0·1–7·0) by age 15 years. 100% coverage at birth reduced tuberculosis deaths by 16·5% (0·7–41·9). Later administration increased tuberculosis deaths—eg, BCG vaccination at 6 weeks, the recommended age of DTP1, increased tuberculosis deaths by 0·2% (0–0·4), even if BCG reached DTP1 coverage levels (94% at 3 years).

Interpretation

Reducing delays and increasing coverage at birth would substantially reduce global paediatric tuberculosis mortality. Modelled scenarios whereby BCG was administered later in the infant schedule were all estimated to increase tuberculosis deaths, even with increased coverage. The WHO recommendation for BCG at birth should be maintained and emphasised.

Funding

WHO.

Health workers' perceptions and challenges in implementing meningococcal serogroup a conjugate vaccine in the routine childhood immunization schedule in Burkina Faso

BACKGROUND

Meningococcal serogroup A conjugate vaccine (MACV) was introduced in 2017 into the routine childhood immunization schedule (at 15-18 months of age) in Burkina Faso to help reduce meningococcal meningitis burden. MACV was scheduled to be co-administered with the second dose of measles-containing vaccine (MCV2), a vaccine already in the national schedule. One year following the introduction of MACV, an assessment was conducted to qualitatively examine health workers' perceptions of MACV introduction, identify barriers to uptake, and explore opportunities to improve coverage.

METHODS

Twelve in-depth interviews were conducted with different cadres of health workers in four purposively selected districts in Burkina Faso. Districts were selected to include urban and rural areas as well as high and low MCV2 coverage areas. Respondents included health workers at the following levels: regional health managers (n = 4), district health managers (n = 4), and frontline healthcare providers (n = 4). All interviews were recorded, transcribed, and thematically analyzed using qualitative content analysis.

RESULTS

Four themes emerged around supply and health systems barriers, demand-related barriers, specific challenges related to MACV and MCV2 co-administration, and motivations and efforts to improve vaccination coverage. Supply and health systems barriers included aging cold chain equipment, staff shortages, overworked and poorly trained staff, insufficient supplies and financial resources, and challenges with implementing community outreach activities. Health workers largely viewed MACV introduction as a source of motivation for caregivers to bring their children for the 15- to 18-month visit. However, they also pointed to demand barriers, including cultural practices that sometimes discourage vaccination, misconceptions about vaccines, and religious beliefs. Challenges in co-administering MACV and MCV2 were mainly related to reluctance among health workers to open multi-dose vials unless enough children were present to avoid wastage.

CONCLUSIONS

To improve effective administration of vaccines in the second-year of life, adequate operational and programmatic planning, training, communication, and monitoring are necessary. Moreover, clear policy communication is needed to help ensure that health workers do not refrain from opening multi-dose vials for small numbers of children.

Early BCG Vaccination, Hospitalizations, and Hospital Deaths: Analysis of a Secondary Outcome in 3 Randomized Trials from Guinea-Bissau

Background

This study was performed to examine the effects of early BCG vaccination on the risk, cause, and severity of infant hospitalizations. The analysis included 3 trials randomizing low-weight neonates to early BCG vaccination (intervention) versus no BCG vaccination (usual practice in low-weight neonates, control), with hospitalizations as secondary outcome.

Methods

Hospitalization data were collected at the pediatric ward of the National Hospital. Effects of BCG vaccination on hospitalization risk were assessed in Cox models providing overall and major disease-group incidence rate ratios (IRRs). Severity was assessed by means of in-hospital case-fatality rates and compared by group as cohort study risk ratios (RRs).

Results

Among 6583 infants (3297 in BCG group, 3286 controls), there were 908 infant hospitalizations (450 BCG, 458 controls) and 135 in-hospital deaths (56 BCG, 79 controls). The neonatal (28 days), 6-week, and infant (1-year) BCG versus control hospitalization IRRs were 0.97 (95% confidence interval [CI], .72-1.31), 0.95 (.73-1.24), and 0.96 (.84-1.10). Corresponding BCG versus control case-fatality rate RRs were 0.58 (95% CI, .35-.94), 0.56 (.35-.90), and 0.72 (.53-.99). BCG vaccination tended to reduce neonatal and infant sepsis hospitalization rates (IRR, 0.75 [95% CI, .50-1.13] and 0.78 [.55-1.11], respectively), and it reduced the neonatal in-hospital sepsis mortality rate (RR, 0.46; 95% CI, .22-.98). There were no confirmed hospitalizations for tuberculosis.

Conclusions

BCG vaccination did not affect hospitalization rates but reduced in-hospital mortality rates significantly, primarily by preventing fatal cases of sepsis. The observed beneficial effects of BCG on the in-hospital mortality rate were entirely nonspecific.

Clinical Trials Registration

NCT00146302, NCT00168610, and NCT00625482.

Can earlier BCG vaccination reduce early infant mortality? Study protocol for a cluster randomised trial in Guinea-Bissau

INTRODUCTION

The BCG vaccine is designed to protect against tuberculosis, but the vaccine may have broader effects. In 2014, the Strategic Advisory Group of Experts on Immunization reviewed the literature on non-specific effects of BCG, and concluded that the evidence was consistent with beneficial non-specific effects and requested further randomised trials.

METHODS AND ANALYSES

Within the Bandim Health Project's urban and rural health and demographic surveillance systems, we will conduct a cluster-randomised trial in six suburban districts and 55 rural villages. Infants are enrolled at a home visit before 72 hours of life. In intervention clusters, children are vaccinated with BCG and oral polio vaccine (OPV). In control clusters, the caregivers are informed about vaccination opportunities. Using Cox-proportional hazards models, we will test whether BCG and OPV provided at a single home visit can reduce early infant mortality up to 60 days.The trial was initiated with a pilot study in Biombo region in June 2015. The trial was scaled up to full study including Oio and Cacheu regions in July 2016. The trial was expanded to include the urban study area in July 2017.

ETHICS AND DISSEMINATION

BCG vaccination is delayed in many low-income settings. WHO-recommended home visits are resource demanding and vaccines are not part of the recommendation. Utilising the home visits to provide BCG and OPV may provide countries with a further incentive to introduce a single home visit. In countries, where home visits are already in place, vaccines can easily be added to reduce early infant mortality. The trial is approved by the Guinean Ethical Committee (Reference number: 0016/CNES/INASA/2015) and the Danish Ethics Committee has given its consultative approval. The results of the trial will be published in international peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02504203; Pre-results.

Developing the concept of beneficial non-specific effect of live vaccines with epidemiological studies

BACKGROUND

Epidemiological and immunological studies are increasingly reporting non-specific effects (NSEs) of vaccines; i.e. vaccines may affect the risk and severity of non-targeted infections. We reviewed how epidemiological studies developed the concept of beneficial NSEs of live vaccines.

SOURCES

This is a personal narrative of how we came to pursue the concept of NSEs in studies of measles vaccine (MV) from the late 1970s. We also searched Pubmed for epidemiological studies of nonspecific/non-specific effects (NSEs) of the most common human vaccines.

CONTENT

When smallpox vaccine was introduced around 1800, bacillus Calmette-Guérin (BCG) against tuberculosis in the 1920s and oral polio vaccine (OPV) in the 1960s, there were suggestions that these live attenuated vaccines reduced mortality more than expected. However, scientific follow-up was limited and the concept of beneficial NSEs did not become mainstream. We observed beneficial NSEs after MV was introduced in low-income countries in the 1970s. Subsequent observational studies and randomized trials confirmed beneficial NSEs of smallpox vaccine, BCG and OPV. Recently, beneficial NSEs have been claimed for the non-live diphtheria-tetanus-pertussis and rabies vaccines. However, no non-live vaccine has yet been documented to produce beneficial NSEs.

IMPLICATIONS

Observational and experimental research has shown beneficial NSEs of four live attenuated vaccines: smallpox vaccine, BCG, OPV and MV. With immunological evidence now supporting the epidemiological observations, it is urgent to take both the specific and NSEs into account in the planning of vaccination programmes.

Household costs of seeking BCG vaccination in rural Guinea-Bissau

In Guinea-Bissau, a vial of BCG vaccine is often not opened unless 10 infants are present for vaccination, with the aim of reducing vaccine wastage. This causes delays in vaccination, as previously demonstrated in Guinea-Bissau and other low-income countries. Reducing wastage of BCG vaccine to save money may deprive infants of important health benefits and transfer costs from the vaccination programme to mothers. Using the Bandim Health Project's rural Health and Demographic Surveillance System, we interviewed mothers of infants aged 1-11 months about household costs of seeking BCG vaccination. On average mothers took their infant for BCG vaccination 1.26 times before obtaining the vaccine. For mothers who had sought BCG vaccine for their infants the average cost was 1.89 USD for each BCG-vaccinated infant. Among BCG-unvaccinated infants at the time of interview, 42% had brought their infant for BCG vaccination in vain at an average cost of 2.83 USD.

Cohort profile : Bandim Health Project's (BHP) rural Health and Demographic Surveillance System (HDSS)-a nationally representative HDSS in Guinea-Bissau

PURPOSE

Bandim Health Project (BHP) monitors health and survival of women and children in a nationally representative rural Health and Demographic Surveillance System (HDSS) in Guinea-Bissau. The HDSS was set up in 1989-1990 to collect data on health interventions and child mortality.

PARTICIPANTS

The HDSS covers 182 randomly selected clusters across the whole country. The cohort is open, and women and children enter the cohort, when they move into the selected clusters, and leave the cohort, when they move out or die, or when children reach 5 years of age. Data are collected through biannual or more frequent household visits. At all village visits, information on pregnancies, vital status, vaccination status, arm circumference, use of bed nets and other basic information is collected for women and children. Today, more than 25 000 women and 23 000 children below the age of 5 years are under surveillance.

FINDINGS TO DATE

Research from the BHP has given rise to the hypothesis that vaccines, in addition to their targeted effects, have important non-specific effects altering the susceptibility to other infections. Initially, it was observed that mortality among children vaccinated with the live BCG or measles vaccines was much lower than the mortality among unvaccinated children, a difference, which could not be explained by prevention of tuberculosis and measles infections. In contrast, mortality tended to be higher for children who had received the non-live Diphtheria-Tetanus-Pertussis vaccine compared with children who had not received this vaccine. Since the effect differed for the different vaccines, no bias explained the contrasting findings.

FUTURE PLANS

New health interventions are introduced with little assessment of real-life effects. Through the HDSS, we can describe both the implementation of interventions (eg, the vaccination programme) and their effects. Furthermore, the intensive follow-up allows the implementation of randomised trials testing potential better vaccination programmes.

Determinants of BCG vaccination coverage in Ethiopia: a cross-sectional survey

OBJECTIVE

The objective of this study is to assess the determinants of BCG vaccination in Ethiopia from 2016 Ethiopia Demographic and Health Survey (EDHS).

SETTING

Since Ethiopia has nine regional states and two administrative cities, sample was taken from all the divisions. The population-based sample was intended to provide estimates of key indicators for the country.

PARTICIPANT

The sampling frame used for the 2016 EDHS is the Ethiopia Population and Housing Census. From 15 683 women recorded in EDHS dataset, women with no child (n=10 379) were excluded from the study. Therefore, the total sample size for this study was 5304 women. The outcome variable was BCG immunisation status of children.

RESULT

Out of the study participants (n=5304), the majority were in between 20 and 34 years of age (73.8%). The median age of the respondents was 28.4 (SD=±6.5) years old. Prevalence of BCG vaccination was 63.6% (n=3373) and BCG vaccination coverage in urban residents was higher (88%) than rural residents (57.3%). Mothers' age between 20 up to 34 (Adjusted odds ratio (AOR)=1.48; 95% CI: 1.13 to 1.93) and between 35 up to 49 (AOR=1.83; 95% CI: 1.35 to 2.46) were more likely to vaccinate their child's than those mothers' age less than 20. Mothers settled in urban areas were two times more likely to vaccinate their child's than those living in rural areas (AOR=1.94; 95% CI: 1.45 to 2.60). Mothers with greater antenatal visits show higher BCG vaccination, Antenatal Care (ANC) 4 and above (AOR=3.48; 95% CI: 2.91 to 4.15). BCG vaccination is higher for mothers delivered at non-governmental organisation health facility than home (AOR=2.9; 95% CI: 1.69 to 4.96). Maternal occupation and wealth index also had a significant association with BCG vaccination.

CONCLUSION

BCG vaccination coverage, in this study, was lower and determinant factors for BCG vaccination were residence, mother's age, place of delivery, mother's antenatal visit, wealth index and mother's occupation.

The real-life number of neonatal doses of Bacille Calmette-Guérin vaccine in a 20-dose vial

BACKGROUND

Reducing vaccine wastage is important. Bacille Calmette-Guérin (BCG) vaccine is produced in vials of 20 infant doses. The reconstituted vaccine is discarded after 4-6 hours. Therefore, to reduce vaccine wastage, a 20-dose vial of BCG is often only opened if at least 10-12 infants are present, jeopardising BCG vaccination coverage and timely vaccination. We observed that nurses were not able to withdraw 20 doses from the vials and aimed to quantify how many doses could be obtained from these vials by experienced nurses under real-life circumstances.

METHODS

At the maternity ward of the national hospital in Guinea-Bissau, since 2002 the same two nurses have been vaccinating all eligible children with BCG before discharge. During a month in 2015, within a randomised trial comparing BCG-Denmark and BCG-Russia, we registered how many doses the nurses were able to withdraw from the two types of vaccine vials.

RESULTS

The median number of doses which it was possible to withdraw from the vials was 13 (range 11-17): 13 (11-16) for BCG-Denmark (based on 39 vials) and 15 (12-17) for BCG-Russia (based on 29 vials).

CONCLUSIONS

In real life, experienced nurses could only obtain 13-15 doses from the 20-dose vials. Thus, vaccine wastage is much lower than assumed. Adjusting practice to the real-life number of doses would immediately suggest vials should be opened if 7 rather than 10 infants are present. As other studies have indicated that BCG may have beneficial non-specific effects on overall mortality, the potential gain by opening a 20-dose vial even for one child may be considerable.

Community perception regarding childhood vaccinations and its implications for effectiveness: a qualitative study in rural Burkina Faso

Background

Vaccination has contributed to major reductions in global morbidity and mortality, but there remain significant coverage gaps. Better knowledge on the interplay between population and health systems regarding provision of vaccination information and regarding health staff organization during the immunization sessions appears to be important for improvements of vaccination effectiveness.

Methods

The study was conducted in the Nouna Health and Demographic Surveillance System (HDSS) area, rural Burkina Faso, from March to April 2014. We employed a combination of in-depth interviews (n = 29) and focus group discussions (n = 4) including children’s mothers, health workers, godmothers, community health workers and traditional healers. A thematic analysis was performed. All material was transcribed, translated and analyzed using the software ATLAS.ti4.2.

Results

There was better social mobilization in the rural areas as compared to the urban area. Most mothers know the Expanded Program of Immunization (EPI) target diseases, and the importance to immunize their children. However, the great majority of informants reported that mothers don’t know the vaccination schedule. There is awareness that some children are incompletely vaccinated. Mentioned reasons for that were migration, mothers being busy with their work, the practice of not opening vaccine vials unless a critical number of children are present, poor interaction between women and health workers during immunization sessions, potential adverse events associated with vaccination, geographic inaccessibility during rainy season, and lack of information.

Conclusions

Well organized vaccination programs are a key factor to improve child health and there is a clear need to consider community perceptions on program performance. In Burkina Faso, a number of factors have been identified which need attention by the EPI managers for further improvement of program effectiveness.

BCG vaccination in southern rural Mozambique: an overview of coverage and its determinants based on data from the demographic and health surveillance system in the district of Manhiça

Background

Over the past four decades, the World Health Organization established the Expanded Programme on Immunization (EPI) to foster universal access to all relevant vaccines for all children at risk. The success of this program has been undeniable, but requires periodic monitoring to ensure that coverage rates remain high. The aim of this study was to measure the BCG vaccination coverage in Manhiça district, a high TB burden rural area of Southern Mozambique and to investigate factors that may be associated with BCG vaccination.

Methods

We used data from the Health and Demographic Surveillance System (HDSS) run by the Manhiça Health Research Centre (CISM) in the district of Manhiça. A questionnaire was added in the annual HDSS round visits to retrospectively collect the vaccination history of children under the age of 3 years. Vaccinations are registered in the National Health Cards which are universally distributed at birth. This information was collected for children born from 2011 to 2014. Data on whether a child was vaccinated for BCG were collected from these National Health Cards and/or BCG scar assessment.

Results

A total of 10,875 number of children were eligible for the study and 7903 presented the health card. BCG coverage was 97.4% for children holding a health card. A BCG-compatible scar was observed in 99.0% of all children and in 99.6% of children with recorded BCG in the card. A total of 93.4% of children had been vaccinated with BCG within their first 28 days of life. None of the factors analysed were found to be associated with lack of BCG vaccination except for living in the municipality of Maluana compared to living in the municipality of Manhiça; (OR = 1.89, 95% CI: 1.18-3.00). Coverage for other EPI vaccines during the first year of life was similarly high, but decreased for subsequent doses.

Conclusions

BCG coverage is high and timely administered. Almost all vaccinated infants develop scar, which is a useful proxy for monitoring BCG vaccine implementation.

Electronic supplementary material

The online version of this article (10.1186/s12887-018-1003-4) contains supplementary material, which is available to authorized users.

Determinants of BCG scarification among children in rural Guinea-Bissau: A prospective cohort study

Background: Bacillus Calmette-Guérin (BCG) vaccination may have beneficial non-specific effects on child survival, the effects being stronger for children developing a scar. In a prospective cohort study, we examined determinants for not developing a BCG scar within 6 months of vaccination.

Methods: Bandim Health Project (BHP) runs a Health and Demographic Surveillance System site in rural Guinea-Bissau. BHP provides BCG at monthly visits. We studied determinants for not developing a BCG scar using binomial regression models to obtain relative risks (RR).

Results: From May 2012 until October 2014, BHP nurses vaccinated 2415 infants with BCG. We assessed BCG scar between 6 and 12 months of age for 2156 (89%) of these children and 2115 (98%) had developed a scar. In comparison, among 785 children BCG vaccinated elsewhere, 622 (79%) had a scar, the RR of not having a scar being 10.91 (7.52-15.85) compared with children vaccinated by BHP.

Among children vaccinated by BHP, those receiving the Russian BCG strain were more likely not to develop a scar (RR = 2.98 (1.52–5.81)) compared with children receiving Danish BCG strain. Children with no post-injection wheal or a wheal <3 mm were more likely to not develop a scar (RR = 9.05 (3.69–22.20) and RR = 4.74 (1.96–11.45), respectively). Nutritional status and socioeconomic status were not associated with scarification.

Conclusion: Vaccination technique and vaccine strain were associated with BCG scar development while nutritional status and socioeconomic status were not. Scarring rate may therefore be a better indicator of vaccination programme performance than coverage.

[Analysis of the territorial patterns of the life contexts of children up to 6 years of age and their potential influence on the coverage of immunization programs in Chile]

The aim of this paper was to analyze selected variables that could be involved in vaccination coverage of children in different communal territories of Chile, including the vaccines bacillus Calmette-Guérin (BCG) at birth, pentavalent at 6 months and measles-mumps-rubella (MMR) at 12 months and 6 years, in the period 2008-2011. The methodology includes three phases. The first corresponds to the operationalization of twenty socio-territorial variables that account the general life contexts of the target population. The second phase involves the definition of a scale of values through a panel of experts to weigh the importance of each of the variables. The third phase integrates the information into a spatial decision support system for the identification of territorial patterns, through multi-criteria evaluation and multivariate cluster analysis. The results indicate that it is feasible to group territories into four types. In general terms, it is possible to observe that as the life context improves, higher levels of coverage can be found for each vaccine.

Factors contributing to regional inequalities in acute respiratory infections symptoms among under-five children in Nigeria: a decomposition analysis

BACKGROUND

Acute respiratory infections (ARI) are major causes of morbidity and mortality in many low-income countries. Although factors associated with ARI symptoms in children under 5 years of age have been identified; however, variation in their prevalence resulting from regional-specific proximate determinants has received little attention. Therefore, we aim to investigate the specific regional determinants of overall and wealth-related inequality in children having ARI in Nigeria over a decade.

METHODS

We analyzed trends in development of ARI symptoms among children under 5 years of age in Nigeria using nationally representative cross sectional surveys carried out in 2003, 2008 and 2013. Overall- and household wealth index based- inequality in the distribution of prevalence of ARI symptoms were estimated by region using Gini index and Concentration Index, respectively. Multivariate logistic regressions for complex survey and decomposition analysis for both indexes were used to calculate percentual contribution.

RESULTS

We found a decreasing trend in development of ARI symptoms over the decade between regions. Children in South Western region had reduced likelihood of developing the symptoms. Concentration index (CI) for the prevalence of ARI symptoms over the years and across regions had negative values (all p < 0.05). Gini index (GI) varies from 0.21 in North East to 0.62 in South Western region. Furthermore, the mapping showed that the extent at which both inequalities contribute to ARI symptoms prevalence in each region is different. The four major sources of wealth-related inequalities were poor households, no maternal education, biomass cooking, and rural area. The major contributors to overall inequalities were having a child aged 6 to 23 months, having no maternal education, having no vaccination card, and having a high birth order/short birth interval.

CONCLUSIONS

Although ARI prevalence decreased over the decade, it has remained unequally distributed between regions and over the time. The sources of those inequalities are context sensitive. Thus, in future health promotion initiatives, it is imperative to account for regional variations in the distribution of ARI.

Vaccination coverage and factors associated with adherence to the vaccination schedule in young children of a rural area in Burkina Faso

BACKGROUND

Vaccination is an important tool for reducing infectious disease morbidity and mortality. In the past, less than 80% of children 12-23 months of age were fully immunized in Burkina Faso.

OBJECTIVES

To describe coverage and assess factors associated with adherence to the vaccination schedule in rural area Burkina Faso.

METHODS

The study population was extracted from the Nouna Health and Demographic surveillance system cohort. Data from four rounds of interviews conducted between November 2012 and June 2014 were considered. This study included 4016 children aged 12-23 months. We assessed the effects of several background factors, including sex, factors reflecting access to health care (residence, place of birth), and maternal factors (age, education, marital status), on being fully immunized defined as having received Bacillus Calmette-Guérin (BCG), three doses of diphtheria-tetanus-pertussis and oral polio vaccine, and measles vaccine by 12 months of age. The associations were studied using binomial regression to derive prevalence ratios (PRs) in univariate and multivariate regression models.

RESULTS

The full vaccination coverage increased significantly over time (72% in 2012, 79% in 2013, and 81% in 2014, p = 0.003), and the coverage was significantly lower in urban than in rural areas (PR 0.84; 0.80-0.89). Vaccination coverage was neither influenced by sex nor influenced by place of birth or by maternal factors.

CONCLUSION

The study documented a further improvement in full vaccination coverage in Burkina Faso in recent years and better vaccination coverage in rural than in urban areas. The organization of healthcare systems with systematic outreach activities in the rural areas may explain the difference between rural and urban areas.

Barriers to timely administration of birth dose vaccines in The Gambia, West Africa

OBJECTIVE

Although vaccine coverage in infants in sub-Saharan Africa is high, this is estimated at the age of 6-12 months. There is little information on the timely administration of birth dose vaccines. The objective of this study was to assess the timing of birth dose vaccines (hepatitis B, BCG and oral polio) and reasons for delayed administration in The Gambia.

METHODS

We used vaccination data from the Farafenni Health and Demographic Surveillance System (FHDSS) between 2004 and 2014. Coverage was calculated at birth (0-1 day), day 7, day 28, 6 months and 1 year of age. Logistic regression models were used to identify demographic and socio-economic variables associated with vaccination by day 7 in children born between 2011 and 2014.

RESULTS

Most of the 10,851 children had received the first dose of hepatitis B virus (HBV) vaccine by the age of 6 months (93.1%). Nevertheless, only 1.1% of them were vaccinated at birth, 5.4% by day 7, and 58.4% by day 28. Vaccination by day 7 was associated with living in urban areas (West rural: adjusted OR (AOR)=6.13, 95%CI: 3.20-11.75, east rural: AOR=6.72, 95%CI: 3.66-12.33) and maternal education (senior-educations: AOR=2.43, 95%CI: 1.17-5.06); and inversely associated with distance to vaccination delivery points (≧2km: AOR=0.41, 95%CI: 0.24-0.70), and Fula ethnicity (AOR=0.60, 95%CI: 0.40-0.91).

CONCLUSION

Vaccine coverage in The Gambia is high but infants are usually vaccinated after the neonatal period. Interventions to ensure the implementation of national vaccination policies are urgently needed.

Development of BCG Scar and Subsequent Morbidity and Mortality in Rural Guinea-Bissau

BACKGROUND

Previous studies have found that BCG vaccination has nonspecific beneficial effects on child survival, especially among children who developed a BCG scar. These studies have mostly been done in settings with a high scar frequency. In rural Guinea-Bissau, many children do not develop a scar; we tested the hypothesis that among BCG-vaccinated children, a vaccination scar was associated with lower mortality and fewer hospital admissions.

METHODS

During 2009-2011, children <5 years of age in villages followed by Bandim Health Project's demographic surveillance system had their scar status assessed at semiannual visits. We compared mortality and hospital admission rates of scar-positive and scar-negative BCG-vaccinated children during 6 months of follow-up in Cox proportional hazards models.

RESULTS

Among 15 911 BCG-vaccinated children, only 52% had a scar. There were 106 non-injury-related deaths among scar-positive children and 137 among scar-negative children. The mortality rate ratio (MRR) was 0.74 (95% confidence interval [CI], .56-.96) overall; 0.48 (95% CI, .26-.90) in infancy, 0.69 (95% CI, .45-1.05) in the second year of life, and 0.89 (95% CI, .61-1.31) in the third-fifth year of life. The association between scar positivity and lower mortality differed significantly by cause of death and was strongest for respiratory infections (MRR, 0.20 [95% CI, .07-.55]). There were 99 hospital admissions among scar-positive children and 125 admissions among scar-negative children, resulting in an incidence rate ratio of 0.74 (95% CI, .60-.92).

CONCLUSIONS

Among BCG-vaccinated children in a setting with low scar prevalence, having a scar is associated with lower mortality and morbidity. BCG scar prevalence may be an important marker of vaccination program quality.