Effect of vitamin A supplementation with BCG vaccine at birth on vitamin A status at 6 wk and 4 mo of age

Effects of neonatal nutrition interventions on neonatal mortality and child health and development outcomes: A systematic review

Background

The last two decades have seen a significant decrease in mortality for children <5 years of age in low and middle-income countries (LMICs); however, neonatal (age, 0-28 days) mortality has not decreased at the same rate. We assessed three neonatal nutritional interventions that have the potential of reducing morbidity and mortality during infancy in LMICs.

Objectives

To determine the efficacy and effectiveness of synthetic vitamin A, dextrose oral gel, and probiotic supplementation during the neonatal period.

Search Methods

We conducted electronic searches for relevant studies on the following databases: PubMed, CINAHL, LILACS, SCOPUS, and CENTRAL, Cochrane Central Register for Controlled Trials, up to November 27, 2019.

Selection Criteria

We aimed to include randomized and quasi-experimental studies. The target population was neonates in LMICs. The interventions included synthetic vitamin A supplementation, oral dextrose gel supplementation, and probiotic supplementation during the neonatal period. We included studies from the community and hospital settings irrespective of the gestational age or birth weight of the neonate.

Data Collection and Analysis

Two authors screened the titles and extracted the data from selected studies. The risk of bias (ROB) in the included studies was assessed according to the Cochrane Handbook of Systematic Reviews. The primary outcome was all-cause mortality. The secondary outcomes were neonatal sepsis, necrotizing enterocolitis (NEC), prevention and treatment of neonatal hypoglycaemia, adverse events, and neurodevelopmental outcomes. Data were meta-analyzed by random effect models to obtain relative risk (RR) and 95% confidence interval (CI) for dichotomous outcomes and mean difference with 95% CI for continuous outcomes. The overall rating of evidence was determined by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Main Results

Sixteen randomized studies (total participants 169,366) assessed the effect of vitamin A supplementation during the neonatal period. All studies were conducted in low- and middle-income (LMIC) countries. Thirteen studies were conducted in the community setting and three studies were conducted in the hospital setting, specifically in neonatal intensive care units. Studies were conducted in 10 different countries including India (four studies), Guinea-Bissau (three studies), Bangladesh (two studies), and one study each in China, Ghana, Indonesia, Nepal, Pakistan, Tanzania, and Zimbabwe. The overall ROB was low in most of the included studies for neonatal vitamin A supplementation. The pooled results from the community based randomized studies showed that there was no significant difference in all-cause mortality in the vitamin A (intervention) group compared to controls at 1 month (RR, 0.99; 95% CI, 0.90-1.08; six studies with 126,548 participants, statistical heterogeneity I 2 0%, funnel plot symmetrical, grade rating high), 6 months (RR, 0.98; 95% CI, 0.89-1.07; 12 studies with 154,940 participants, statistical heterogeneity I 2 43%, funnel plot symmetrical, GRADE quality high) and 12 months of age (RR, 1.04; 95% CI, 0.94-1.14; eight studies with 118,376 participants, statistical heterogeneity I 2 46%, funnel plot symmetrical, GRADE quality high). Neonatal vitamin A supplementation increased the incidence of bulging fontanelle by 53% compared to control (RR, 1.53; 95% CI, 1.12-2.09; six studies with 100,256 participants, statistical heterogeneity I 2 65%, funnel plot symmetrical, GRADE quality high). We did not identify any experimental study that addressed the use of dextrose gel for the prevention and/or treatment of neonatal hypoglycaemia in LMIC. Thirty-three studies assessed the effect of probiotic supplementation during the neonatal period (total participants 11,595; probiotics: 5854 and controls: 5741). All of the included studies were conducted in LMIC and were randomized. Most of the studies were done in the hospital setting and included participants who were preterm (born < 37 weeks gestation) and/or low birth weight (<2500 g birth weight). Studies were conducted in 13 different countries with 10 studies conducted in India, six studies in Turkey, three studies each in China and Iran, two each in Mexico and South Africa, and one each in Bangladesh, Brazil, Colombia, Indonesia, Nepal, Pakistan, and Thailand. Three studies were at high ROB due to lack of appropriate randomization sequence or allocation concealment. Combined data from 25 studies showed that probiotic supplementation reduced all-cause mortality by 20% compared to controls (RR, 0.80; 95% CI, 0.66-0.96; total number of participants 10,998, number needed to treat 100, statistical heterogeneity I 2 0%, funnel plot symmetrical, GRADE quality high). Twenty-nine studies reported the effect of probiotics on the incidence of NEC, and the combined results showed a relative reduction of 54% in the intervention group compared to controls (RR, 0.46; 95% CI, 0.35-0.59; total number of participants 5574, number needed to treat 17, statistical heterogeneity I 2 24%, funnel plot symmetrical, GRADE quality high). Twenty-one studies assessed the effect of probiotic supplementation during the neonatal period on neonatal sepsis, and the combined results showed a relative reduction of 22% in the intervention group compared to controls (RR, 0.78; 95% CI, 0.70-0.86; total number of participants 9105, number needed to treat 14, statistical heterogeneity I 2 23%, funnel plot symmetrical, GRADE quality high).

Authors' Conclusions

Vitamin A supplementation during the neonatal period does not reduce all-cause neonatal or infant mortality in LMICs in the community setting. However, neonatal vitamin A supplementation increases the risk of Bulging Fontanelle. No experimental or quasi-experimental studies were available from LMICs to assess the effect of dextrose gel supplementation for the prevention or treatment of neonatal hypoglycaemia. Probiotic supplementation during the neonatal period seems to reduce all-cause mortality, NEC, and sepsis in babies born with low birth weight and/or preterm in the hospital setting. There was clinical heterogeneity in the use of probiotics, and we could not recommend any single strain of probiotics for wider use based on these results. There was a lack of studies on probiotic supplementation in the community setting. More research is needed to assess the effect of probiotics administered to neonates in-home/community setting in LMICs.

Metabolism of Neonatal Vitamin A Supplementation: A Systematic Review

A systematic review was conducted to summarize the absorption, transport, storage, and metabolism of oral neonatal vitamin A supplementation (NVAS). This review focused specifically on the neonatal period (first 28 d of life for humans) to inform guidance by WHO on recommendations related to NVAS. A systematic search of international and regional databases was conducted. Inclusion criteria were human or animal studies that gave oral vitamin A as a single or limited number of doses to apparently healthy neonates. Studies evaluating fortification or food-based approaches, dosing with retinoic acid, or studies of neonatal models of disease were excluded. The search retrieved 8847 unique records. After screening by title and abstract, 88 were screened using the full text, and 35 records met inclusion criteria: 13 human and 22 animal studies. Studies indicate that high-dose NVAS is absorbed well by neonates, typically mirroring fat absorption. Doses were primarily stored in the liver and transiently increased in the lung, kidney, spleen, adrenal glands, brain, skin, and adipose tissue, generally with a dose-response. Serum retinol and retinyl esters also transiently increased following NVAS. Although minimal acute adverse effects are noted, there is a lack of data supporting NVAS for improving organ maturation or sustained delivery to target organs. Research gaps include the physiological effects of the short-term increase of vitamin A concentrations in extrahepatic tissues, or whether there are unknown adverse effects over time.

Lessons Learned from the Testing of Neonatal Vitamin A Supplementation

A total of 12 trials have tested the effect of neonatal vitamin A supplementation (NVAS) on mortality. Overall, NVAS had no effect on mortality, but results were heterogeneous. Two competing hypotheses have been put forward to explain the divergent effects: A) NVAS works by preventing vitamin A deficiency (VAD) and not all countries have VAD; B) NVAS interacts negatively with subsequent diphtheria-tetanus-pertussis (DTP) vaccine, increasing mortality in females; in countries with low DTP coverage NVAS may have a beneficial effect. Only hypothesis A was tested in a recent meta-analysis; there is no strong empirical support for hypothesis A and it would not explain observed negative effects in some settings. Hypothesis B accounts for most observations. However, so far it has only been tested properly in a few trials. If hypothesis B is correct, it has major consequences for the understanding of the effects of vitamin A, and for the VAS policy in older children. As a WHO priority, the DTP coverage is bound to increase, and therefore hypothesis B urgently needs to be tested.

Neonatal vitamin A supplementation for the prevention of mortality and morbidity in term neonates in low and middle income countries

BACKGROUND

Vitamin A deficiency is a major public health problem in low and middle income countries. Vitamin A supplementation in children six months of age and older has been found to be beneficial, but no effect of supplementation has been noted for children between one and five months of age. Supplementation during the neonatal period has been suggested to have an impact by increasing body stores in early infancy.

OBJECTIVES

To evaluate the role of vitamin A supplementation for term neonates in low and middle income countries with respect to prevention of mortality and morbidity.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2), MEDLINE via PubMed (1966 to 13 March 2016), Embase (1980 to 13 March 2016) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 13 March 2016). We also searched clinical trials databases, conference proceedings and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials. Also trials with a factorial design.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted study data. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence.

MAIN RESULTS

We included 12 trials (168,460 neonates) in this review, with only a few trials reporting disaggregated data for term infants. Therefore, we analysed data and presented estimates for term infants (when specified) and for all infants.Data for term neonates from three studies did not show a statistically significant effect on the risk of infant mortality at six months in the vitamin A group compared with the control group (typical risk ratio (RR) 0.80; 95% confidence interval (CI) 0.54 to 1.18; I² = 63%). Analysis of data for all infants from 11 studies revealed no evidence of a significant reduction in the risk of infant mortality at six months among neonates supplemented with vitamin A compared with control neonates (typical RR 0.98, 95% CI 0.89 to 1.07; I² = 47%). We observed similar results for infant mortality at 12 months of age with no significant effect of vitamin A compared with control (typical RR 1.04, 95% CI 0.94 to 1.15; I² = 47%). Limited data were available for the outcomes of cause-specific mortality and morbidity, vitamin A deficiency, anaemia and adverse events.

AUTHORS' CONCLUSIONS

Given the high burden of death among children younger than five years of age in low and middle income countries, and the fact that mortality in infancy is a major contributory cause, it is critical to obtain sound scientific evidence of the effect of vitamin A supplementation during the neonatal period on infant mortality and morbidity. Evidence provided in this review does not indicate a potential beneficial effect of vitamin A supplementation among neonates at birth in reducing mortality during the first six months or 12 months of life. Given this finding and the absence of a clear indication of the biological mechanism through which vitamin A could affect mortality, along with substantial conflicting findings from individual studies conducted in settings with potentially varying levels of maternal vitamin A deficiency and infant mortality, absence of follow-up studies assessing any long-term impact of a bulging fontanelle after supplementation and the finding of a potentially harmful effect among female infants, additional research is warranted before a decision can be reached regarding policy recommendations for this intervention.

The effects of vitamin A supplementation with measles vaccine on leucocyte counts and in vitro cytokine production

As WHO recommends vitamin A supplementation (VAS) at vaccination contacts after age 6 months, many children receive VAS together with measles vaccine (MV). We aimed to investigate the immunological effect of VAS given with MV. Within a randomised placebo-controlled trial investigating the effect on overall mortality of providing VAS with vaccines in Guinea-Bissau, we conducted an immunological sub-study of VAS v. placebo with MV, analysing leucocyte counts, whole blood in vitro cytokine production, vitamin A status and concentration of C-reactive protein (CRP). VAS compared with placebo was associated with an increased frequency of CRP ≥ 5 mg/l (28 v. 12%; P=0·005). Six weeks after supplementation, VAS had significant sex-differential effects on leucocyte, lymphocyte, monocyte and basophil cell counts, decreasing them in males but increasing them in females. Mainly in females, the effect of VAS on cytokine responses differed by previous VAS: in previous VAS recipients, VAS increased the pro-inflammatory and T helper cell type 1 (Th1) cytokine responses, whereas VAS decreased these responses in previously unsupplemented children. In previous VAS recipients, VAS was associated with increased IFN-γ responses to phytohaemagglutinin in females (geometric mean ratio (GMR): 3·97; 95% CI 1·44, 10·90) but not in males (GMR 0·44; 95% CI 0·14, 1·42); the opposite was observed in previously unsupplemented children. Our results corroborate that VAS provided with MV has immunological effects, which may depend on sex and previous VAS. VAS may increase the number of leucocytes, but also repress both the innate and lymphocyte-derived cytokine responses in females, whereas this repression may be opposite if the females have previously received VAS.

Neonatal vitamin A supplementation associated with increased atopy in girls

BACKGROUND

Neonatal vitamin A supplementation (NVAS) is currently being considered as policy in countries at risk of deficiency. A previous study suggested that NVAS may be associated with increased atopy. We examined the effect of NVAS on atopy by conducting long-term follow-up of a previous randomized controlled trial in Guinea-Bissau.

METHODS

In 2002-2004, we randomized 4345 normal birthweight neonates to NVAS (50 000 IU retinyl palmitate) or placebo together with their Bacillus Calmette-Guérin vaccination. In 2013, we visited the 1692 (39%) children now aged 8-10 years who were still living in the study area, and 1478 (87%) were found at home. Provided consent, a skin prick test was performed, and history of allergic symptoms was recorded. Associations of NVAS and atopy (defined as skin prick test reaction of ≥3 mm) were analysed using binomial regression.

RESULTS

Of the 1430 children with a valid skin prick test, 228 (16%) were positive (more boys (20%) than girls (12%), P-value < 0.0001). NVAS did not increase the overall risk of atopy (RR 1.10 [95% CI 0.87-1.40]). However, NVAS was associated with significantly increased risk among females (RR 1.78 [1.17-2.72]) but not among males (0.86 [0.64-1.15], P-value for interaction between NVAS and gender = 0.005). Furthermore, NVAS was associated with increased risk of wheezing among females (RR 1.80 [1.03-3.17], but not among males, P-value for interaction = 0.05).

CONCLUSION

The study corroborated previous observations; NVAS was associated with increased risk of atopy and wheezing, in this study only among females. Further studies on NVAS and atopy are warranted.

An enigma: why vitamin A supplementation does not always reduce mortality even though vitamin A deficiency is associated with increased mortality

BACKGROUND

Vitamin A deficiency (VAD) is associated with increased mortality. To prevent VAD, WHO recommends high-dose vitamin A supplementation (VAS) every 4-6 months for children aged between 6 months and 5 years of age in countries at risk of VAD. The policy is based on randomized clinical trials (RCTs) conducted in the late 1980s and early 1990s. Recent RCTs indicate that the policy may have ceased to be beneficial. In addition, RCTs attempting to extend the benefits to younger children have yielded conflicting results. Stratified analyses suggest that whereas some subgroups benefit more than expected from VAS, other subgroups may experience negative effects.

METHODS AND RESULTS

We reviewed the potential modifiers of the effect of VAS. The variable effect of VAS was not explained by underlying differences in VAD. Rather, the effect may depend on the sex of the child, the vaccine status and previous supplementation with vitamin A. Vitamin A is known to affect the Th1/Th2 balance and, in addition, recent evidence suggests that vitamin A may also induce epigenetic changes leading to down-regulation of the innate immune response. Thus VAS protects against VAD but has also important and long-lasting immunological effects, and the effect of providing VAS may vary depending on the state of the immune system.

CONCLUSIONS

To design optimal VAS programmes which target those who benefit and avoid those harmed, more studies are needed. Work is ongoing to define whether neonatal VAS should be considered in subgroups. In the most recent RCT in older children, VAS doubled the mortality for males but halved mortality for females. Hence, we urgently need to re-assess the effect of VAS on older children in large-scale RCTs powered to study effect modification by sex and other potential effect modifiers, and with nested immunological studies.

High-dose vitamin A with vaccination after 6 months of age: a randomized trial

BACKGROUND

The World Health Organization recommends vitamin A supplementation (VAS) at routine vaccination contacts after 6 months of age based on the assumption that it reduces mortality by 24%. The policy has never been evaluated in randomized controlled trials for its effect on overall mortality. We conducted a randomized double-blind trial to evaluate the effect of VAS with vaccines.

METHODS

We randomized children aged 6 to 23 months 1:1 to VAS (100000 IU if aged 6-11 months, 200000 IU if aged 12-23 months) or placebo at vaccination contacts in Guinea-Bissau. Mortality rates were compared in Cox proportional-hazards models overall, and by gender and vaccine.

RESULTS

Between August 2007 and November 2010, 7587 children were enrolled. Within 6 months of follow-up 80 nonaccident deaths occurred (VAS: 38; placebo: 42). The mortality rate ratio (MRR) comparing VAS versus placebo recipients was 0.91 (95% confidence interval 0.59-1.41) and differed significantly between boys (MRR 1.92 [0.98-3.75]) and girls (MRR 0.45 [0.24-0.87]) (P = .003 for interaction between VAS and gender). At enrollment, 42% (3161/7587) received live measles vaccine, 29% (2154/7587) received inactivated diphtheria-tetanus-pertussis-containing vaccines, and 21% (1610/7587) received both live and inactivated vaccines. The effect of VAS did not differ by vaccine group.

CONCLUSIONS

This is the first randomized controlled trial to assess the effect of the policy on overall mortality. VAS had no overall effect, but the effect differed significantly by gender. More trials to ensure an optimal evidence-based vitamin A policy are warranted.

Two different doses of supplemental vitamin A did not affect mortality of normal-birth-weight neonates in Guinea-Bissau in a randomized controlled trial

Whether neonatal vitamin A supplementation (NVAS) should be policy in areas with vitamin A deficiency is debated. We observed that a smaller dose of vitamin A may decrease mortality more than a larger dose and conducted a randomized, double-blind, placebo-controlled trial in Guinea-Bissau with the primary aim of comparing the effect of 50,000 with 25,000 IU neonatal vitamin A on infant mortality. The secondary aim was to study the effect of NVAS vs. placebo, including a combined analysis of NVAS trials. Between 2004 and 2007, normal-birth-weight neonates were randomly assigned in a 1:1:1 ratio to be administered 2 different doses of vitamin A (50,000 or 25,000 IU) or placebo. Infant mortality rates (MRs) were compared in Cox models providing MR ratios (MRRs). Among 6048 children enrolled, there were 160 deaths in 4125 person-years (MR = 39/1000). There was no difference in mortality between the 2 dosage groups: the MRR for 25,000 vs. 50,000 IU was 0.96 (95% CI: 0.67, 1.38). Neither dose of NVAS was associated with lower mortality than placebo (MRR = 1.28; 95% CI: 0.91, 1.81). In a combined analysis of the present trial and 2 previous NVAS trials in Guinea-Bissau, the effect of receiving NVAS (any dose) vs. placebo was 1.13 (95% CI: 0.94, 1.36) and differed significantly (P = 0.01) between boys (0.80; 95% CI: 0.58, 1.09) and girls (1.35; 95% CI: 1.04, 1.75). We could not confirm that a smaller dose of neonatal vitamin A reduces mortality more than a larger dose. We confirmed 2 other trials in Guinea-Bissau that showed no beneficial effect of NVAS. This trial was registered at clinicaltrials.gov as NCT00168610.

Vitamin A supplementation and risk of atopy: long-term follow-up of a randomized trial of vitamin A supplementation at six and nine months of age

Background

The World Health Organization recommends high-dose vitamin A supplementation (VAS) for children above six months of age in low-income countries. VAS has been associated with up-regulation of the Th2 response. We aimed to determine if VAS is associated with atopy in childhood.

Methods

Infants in Guinea-Bissau were randomly allocated VAS or placebo, either at six and nine months of age, or only at nine months of age. At six months of age, children were furthermore randomized to measles vaccine or inactivated polio vaccine. At nine months of age all children received measles vaccine. Children were revisited seven years later and skin prick testing was performed. Atopy was defined as a skin prick reaction ≥3 mm.

Results

40 of 263 children (15%) were atopic. Overall VAS had no significant effect on the risk of atopy (Prevalence Ratio 1.23; 95% CI 0.69-2.18). The Prevalence Ratio was 1.60 (0.66-3.90) for males and 1.00 (0.46-2.15) for females.

Conclusions

There was no significant effect of VAS in infancy on atopy later in childhood. The role of infant VAS in the development of atopy is still unclear.

Vitamin A supplementation and BCG vaccination at birth may affect atopy in childhood: long-term follow-up of a randomized controlled trial

BACKGROUND

Recent evidence suggests that immunogenic interventions such as vaccines and micronutrients may affect atopic sensitization and atopic disease. We aimed to determine whether neonatal BCG vaccination, vitamin A supplementation and other vaccinations affect atopy in childhood.

METHODS

In Guinea-Bissau, low-birthweight infants were randomized to early (intervention) or delayed (usual policy) BCG. A subgroup was also randomly assigned vitamin A supplementation or placebo in a two-by-two factorial design. Participants were followed up at age 3-9 years. The main outcome was atopy defined as skin prick test reaction ≥3 mm. Secondary outcomes were symptoms of eczema, asthma and food allergy.

RESULTS

Two hundred eighty-one children had valid skin prick tests performed, and 14% (39/281) were atopic. There was no significant difference in atopy between the early and delayed BCG groups (OR, 0.71; 95% CI, 0.34-1.47). Atopy was significantly reduced in children who had responded to BCG with a scar (OR, 0.42; 0.19-0.94). Vitamin A supplementation was associated with increased atopy (OR, 2.88; 1.26-6.58), especially in those who received simultaneous BCG (5.99; 1.99-18.1, P = 0.09 for interaction between vitamin A supplementation and BCG). Early vs delayed BCG was not associated with symptoms of atopic disease, but vitamin A supplementation increased odds of wheeze within the past 12 months (OR, 2.45; 1.20-4.96).

CONCLUSIONS

There were no statistically significant effects of early vs delayed BCG on atopy or symptoms of atopic disease. Having a BCG scar was associated with reduced atopy, whereas neonatal vitamin A supplementation was associated with increased atopy.

STUDY REGISTRATION

Clinicaltrials.gov NCT 01420705.

High-dose vitamin A supplementation administered with vaccinations after 6 months of age: sex-differential adverse reactions and morbidity

BACKGROUND

WHO recommends vitamin A supplementation (VAS) at vaccination contacts after six months of age. The effect of this recommendation on mortality has not been evaluated.

METHODS

We tested the effect of VAS at vaccination contacts on mortality in a randomised trial in Guinea-Bissau. In a subgroup within this trial we studied adverse reactions to VAS and whether VAS modified known adverse reactions to live and inactivated vaccines and general morbidity during the first month after supplementation overall and by sex. Children aged 6-17 months were randomised to VAS or placebo at the day of vaccination (day 0). We interviewed the caretaker, assessed the fontanel and measured temperature and local reaction at the injection site at home visits on day 1, 2, 3, 7, 14, 21, and 31. We defined systemic adverse reactions to inactivated and live vaccines as fever on day 1 and 2 and on 4-14 respectively. Clinical symptoms associated with increased intracranial pressure (ICP) on day 1 were considered possible adverse reactions to VAS.

RESULTS

In 1673 children VAS had no overall effect on clinical symptoms associated with increased ICP (Relative Risk(RR)=1.07 (95%CI: 0.85-1.35)). However, VAS was associated with such clinical symptoms in boys RR=1.38 (1.00-1.91)) but not in girls (p=0.03 for interaction between VAS and sex). VAS had no effect on fever after inactivated vaccines. VAS had no overall effect on fever after live vaccines (RR=0.86 (0.53-1.39)), but tended to reduce the prevalence of fever in boys (RR=0.58 (0.30-1.14)), but not in girls (RR=1.37 (0.66-2.84)) (p=0.09 for interaction between VAS and sex). VAS was associated with increased local reactions to measles vaccine in both sexes (RR=3.65 (1.20-11.12)).

CONCLUSION

Adverse reactions were rare, mild and transient and may not in their own right cause concern. However, VAS caused sex-differential adverse reactions and may have sex-differential effects on adverse reactions to vaccines.

Determinants of vitamin a deficiency in children between 6 months and 2 years of age in Guinea-Bissau

Background

The World Health Organization (WHO) classifies Guinea-Bissau as having severe vitamin A deficiency (VAD). To date, no national survey has been conducted. We assessed vitamin A status among children in rural Guinea-Bissau to assess status and identify risk factors for VAD.

Methods

In a vitamin A supplementation trial in rural Guinea-Bissau, children aged 6 months to 2 years who were missing one or more vaccines were enrolled, vaccinated and randomized to vitamin A or placebo. Provided consent, a dried blood spot (DBS) sample was obtained from a subgroup of participants prior to supplementation. Vitamin A status and current infection was assessed by an ELISA measuring retinol-binding protein (RBP) and C-reactive protein (CRP). VAD was defined as RBP concentrations equivalent to plasma retinol <0.7 μmol/L; infection was defined as CRP >5 ml/L. In Poisson regression models providing prevalence ratios (PR), we investigated putative risk factors for VAD including sex, age, child factors, maternal factors, season (rainy: June-November; dry: December-May), geography, and use of health services.

Results

Based on DBS from 1102 children, the VAD prevalence was 65.7% (95% confidence interval 62.9-68.5), 11% higher than the WHO estimate of 54.7% (9.9-93.0). If children with infection were excluded, the prevalence was 60.2% (56.7-63.7). In the age group 9–11 months, there was no difference in prevalence of VAD among children who had received previous vaccines in a timely fashion and those who had not. Controlled for infection and other determinants of VAD, the prevalence of VAD was 1.64 (1.49-1.81) times higher in the rainy season compared to the dry, and varied up to 2-fold between ethnic groups and regions. Compared with having an inactivated vaccine as the most recent vaccine, having a live vaccine as the most recent vaccination was associated with lower prevalence of VAD (PR=0.84 (0.74-0.96)).

Conclusions

The prevalence of VAD was high in rural Guinea-Bissau. VAD varied significantly with season, ethnicity, region, and vaccination status.

Trial registration

Clinicaltrials.gov NCT00514891

Early diphtheria-tetanus-pertussis vaccination associated with higher female mortality and no difference in male mortality in a cohort of low birthweight children: an observational study within a randomised trial

BACKGROUND

Studies from low-income countries have suggested that diphtheria-tetanus-pertussis (DTP) vaccine provided after Bacille Calmette-Guerin (BCG) vaccination may have a negative effect on female survival. The authors examined the effect of DTP in a cohort of low birthweight (LBW) infants.

METHODS

2320 LBW newborns were visited at 2, 6 and 12 months of age to assess nutritional and vaccination status. The authors examined survival until the 6-month visit for children who were DTP vaccinated and DTP unvaccinated at the 2-month visit.

RESULTS

Two-thirds of the children had received DTP at 2 months and 50 deaths occurred between the 2-month and 6-month visits. DTP vaccinated children had a better anthropometric status for all indices than DTP unvaccinated children. Small mid-upper arm circumference (MUAC) was the strongest predictor of mortality. The death rate ratio (DRR) for DTP vaccinated versus DTP unvaccinated children differed significantly for girls (DRR 2.45; 95% CI 0.93 to 6.45) and boys (DRR 0.53; 95% CI 0.23 to 1.20) (p=0.018, homogeneity test). Adjusting for MUAC, the overall effect for DTP vaccinated children was 2.62 (95% CI 1.34 to 5.09); DRR was 5.68 (95% CI 1.83 to 17.7) for girls and 1.29 (95% CI 0.56 to 2.97) for boys (p=0.023, homogeneity test). While anthropometric indices were a strong predictor of mortality among boys, there was little or no association for girls.

CONCLUSION

Surprisingly, even though the children with the best nutritional status were vaccinated early, early DTP vaccination was associated with increased mortality for girls.

The effect of at-birth vitamin A supplementation on differential leucocyte counts and in vitro cytokine production: an immunological study nested within a randomised trial in Guinea-Bissau

Vitamin A supplementation (VAS) at birth was not associated with improved survival in a randomised, placebo-controlled trial in Guinea-Bissau. However, a negative sex-differential effect, which became evident after diphtheria-tetanus-pertussis (DTP) vaccination, was noted; among girls who had received DTP, VAS at birth was associated with two-fold higher mortality than placebo. The objective of the present study was to investigate the immunological effects of VAS at birth within a subgroup of participants in the randomised trial. Guided by the mortality results, we further explored whether VAS had a differential effect according to sex and DTP status. At 6 weeks after randomisation and supplementation, we measured differential leucocyte counts and TNF-α, interferon-γ, IL-10, IL-13 and IL-5 production in a whole-blood culture assay. A total of 471 children were included. VAS compared with placebo at birth was associated with a higher proportion of monocytes (relative risk ratio 1·26, 95 % CI 1·07, 1·49, P=0·04), while spontaneous TNF-α production was lower in the VAS group (geometric mean ratio 0·54, 95 % CI, 0·37, 0·78, P=0·001). Stratified analysis showed that VAS was associated with lower TNF-α and IL-10 production for girls without DTP and boys with DTP, resulting in significant three-way interactions between VAS, sex and DTP vaccination status (P=0·03 and P=0·04, respectively) for spontaneous TNF-α and IL-10 production. The results substantiate the potential role of VAS as an immunomodulatory intervention, which has different effects depending on concomitant health interventions and the sex of the recipient.

Does the effect of vitamin A supplements depend on vaccination status? An observational study from Guinea-Bissau

Objective Vitamin A supplementation (VAS) is estimated to reduce all-cause mortality by 24%. Previous studies indicate that the effect of VAS may vary with vaccination status. The authors evaluated the effect of VAS provided in campaigns on child survival overall and by sex and vaccination status at the time of supplementation. Design Observational cohort study. Setting and participants The study was conducted in the urban study area of the Bandim Health Project in Guinea-Bissau. The authors documented participation or non-participation in two national vitamin A campaigns in December 2007 and July 2008 for children between 6 and 35 months of age. Vaccination status was ascertained by inspection of vaccination cards. All children were followed prospectively. Outcome measures Mortality rates for supplemented and non-supplemented children were compared in Cox models providing mortality rate ratios (MRRs). Results The authors obtained information from 93% of 5567 children in 2007 and 90% of 5799 children in 2008. The VAS coverage was 58% in 2007 and 68% in 2008. Mortality in the supplemented group was 1.5% (44 deaths/2873 person-years) and 1.6% (20 deaths/1260 person-years) in the non-supplemented group (adjusted MRR=0.78 (0.46; 1.34)). The effect was similar in boys and girls. Vaccination cards were seen for 86% in 2007 and 84% in 2008. The effect of VAS in children who had measles vaccine as their last vaccine (2814 children, adjusted MRR=0.34 (0.14; 0.85)) differed from the effect in children who had diphtheria-tetanus-pertussis vaccine as their last vaccine (3680 children, adjusted MRR=1.29 (0.52; 3.22), p=0.04 for interaction). Conclusion The effect of VAS differed by most recent vaccination, being beneficial after measles vaccine but not after diphtheria-tetanus-pertussis vaccine.

Effect of vitamin A supplementation in women of reproductive age on cause-specific early and late infant mortality in rural Ghana: ObaapaVitA double-blind, cluster-randomised, placebo-controlled trial

Objectives To assess the effect of vitamin A supplementation in women of reproductive age in Ghana on cause- and age-specific infant mortality. In addition, because of recently published studies from Guinea Bissau, effects on infant mortality by sex and season were assessed. Design Double-blind, cluster-randomised, placebo-controlled trial. Setting 7 contiguous districts in the Brong Ahafo region of Ghana. Participants All women of reproductive age (15-45 years) resident in the study area randomised by cluster of residence. All live born infants from 1 June 2003 to 30 September 2008 followed up through 4-weekly home visits. Intervention Weekly low-dose (25 000 IU) vitamin A. Main outcome measures Early infant mortality (1-5 months); late infant mortality (6-11 months); infection-specific infant mortality (0-11 months). Results 1086 clusters, 62 662 live births, 52 574 infant-years and 3268 deaths yielded HRs (95% CIs) comparing weekly vitamin A with placebo: 1.04 (0.88 to 1.05) early infant mortality; 0.99 (0.84 to 1.18) late infant mortality; 1.03 (0.92 to 1.16) infection-specific infant mortality. There was no evidence of modification of the effect of vitamin A supplementation on infant mortality by sex (Wald statistic =0.07, p=0.80) or season (Wald statistic =0.03, p=0.86). Conclusions This is the largest analysis of cause of infant deaths from Africa to date. Weekly vitamin A supplementation in women of reproductive age has no beneficial or deleterious effect on the causes of infant death to age 6 or 12 months in rural Ghana. Trial registration number http://ClinicalTrials.gov: NCT00211341.

Neonatal vitamin A supplementation for the prevention of mortality and morbidity in term neonates in developing countries

BACKGROUND

Vitamin A deficiency is a major public health problem in developing countries. Vitamin A supplementation in children greater than six months of age has been found to be beneficial, with no effect of supplementation between one to five months. Supplementation in the neonatal period has been suggested to have an impact by increasing body stores in early infancy.

OBJECTIVES

To evaluate the role of vitamin A supplementation in term neonates in developing countries with respect to the prevention of mortality and morbidity.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, May 2010), EMBASE and MEDLINE (1966 to May 2010) via PubMed.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials. Trials with factorial designs were also included.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted the data.

MAIN RESULTS

Seven trials (51,446 neonates) were included in this review, with only few trials reporting disaggregated data for term infants. Therefore, we analysed data and presented estimates for term infants (where specified) followed by all infants.Data for term neonates from three studies showed a statistically significant effect on the risk of infant mortality at six months in the vitamin A group compared with the control group (typical risk ratio (RR) 0.82; 95% CI 0.68 to 0.99; I(2) 63%). Analysis of data for all infants from five studies showed a 14% reduction in the risk of infant mortality at six months in neonates supplemented with vitamin A compared to control; this reduction was statistically significant (typical RR 0.86; 95% CI 0.77 to 0.97; I(2) 39%). These findings should be interpreted with caution, however, due to the small number of included studies, wide confidence intervals with upper levels close to the null effect and statistical heterogeneity. Vitamin A supplementation failed to show any significant effect on infant mortality at 12 months of age compared to control (typical rate ratio 1.03; 95% CI 0.87 to 1.23; I(2) 49%). Limited data were available for the outcomes of cause-specific mortality and morbidity, vitamin A deficiency, anaemia and adverse events.

AUTHORS' CONCLUSIONS

Considering mortality in early infancy being a major contributory cause of overall child mortality for the under five year old group in developing countries, it is critical to obtain sound scientific evidence of the effect of vitamin A supplementation in neonates. Evidence provided in this review does indicate a potential beneficial effect of supplementing neonates with vitamin A at birth for reducing mortality in the first half of infancy. Considering the absence of a clear indication of the biological mechanism and conflicting findings from individual studies in settings with varying levels of maternal vitamin A deficiency and infant mortality, and given four additional ongoing trials with approximately 100,000 neonates being enrolled, we propose a delay in any policy recommendations for neonatal vitamin A supplementation.

The impact of different doses of vitamin A supplementation on male and female mortality. A randomised trial from Guinea-Bissau

Background

Vitamin A supplementation (VAS) given to children between 6 months and 5 years of age is known to reduce mortality in low-income countries. We have previously observed that girls benefit more from a lower dose of VAS than the one recommended by WHO, the effect being strongest if diphtheria-tetanus-pertussis vaccine (DTP) was the most recent vaccination. We aimed to test these observations.

Methods

During national immunisations days in Guinea-Bissau, West Africa, combining oral polio vaccination and VAS, we randomised 8626 children between 6 months and 5 years of age to receive the dose of VAS recommended by WHO or half this dose. Mortality rate ratios (MRRs) were assessed after 6 and 12 month.

Results

The overall mortality rate among participants was lower than expected. There was no significant difference in mortality at 6 months and 12 months of follow up between the low dose VAS group and the recommended dose VAS group. The MRRs were 1.23 (0.60-2.54) after 6 months and 1.17 (0.73-1.87) after 12 months. This tendency was similar in boys and girls. The low dose was not associated with lower mortality in girls if the most recent vaccine was DTP (MRR = 0.60 (0.14-2.50) after 6 months).

Conclusion

Our sample size does not permit firm conclusions since mortality was lower than expected. We could not confirm a beneficial effect of a lower dose of VAS on mortality in girls.

Trial registration

The study was registered under clinicaltrials.gov, number NCT00168636

Vitamin A supplementation at birth might prime the response to subsequent vitamin A supplements in girls. Three year follow-up of a randomized trial

Objectives

Within a randomised trial of neonatal vitamin A supplementation (VAS) in Guinea-Bissau, neonatal VAS did not affect overall infant mortality. We conducted a post-hoc analysis to test the hypothesis that neonatal VAS primes the response to subsequent vitamin A.

Methods

All trial children were offered VAS after follow-up ended at 1 year of age (FU-VAS). We compared mortality between 1 and 3 years of age according to initial randomization to neonatal VAS or placebo in Cox-regression models; we expected that children randomized to neonatal VAS compared with those randomized to placebo would have lower mortality after reception of FU-VAS.

Results

Of 4345 infants enrolled in the original trial, 3646 lived in the study area at 1 year of age and 2958 received FU-VAS. Between 1 and 3 years of age, 112 children died. After FU-VAS, neonatal VAS was associated with lower mortality than placebo: Mortality Rate Ratio (MRR) = 0.54 (95%CI: 0.31–0.94). The effect was more pronounced in girls (MRR = 0.37 (0.16–0.89)) than boys (MRR = 0.73 (0.35–1.51)). The beneficial effect of neonatal VAS may have been particularly strong for girls who received both VAS in a campaign and FU-VAS (MRR = 0.15 (0.03–0.67)). Among children who had not received FU-VAS, mortality in the second and third year of life did not differ according to reception of neonatal VAS or placebo. Hence, in the second and third year of life the effect of neonatal VAS versus placebo was different in girls who had or had not received FU-VAS (p for homogeneity = 0.01).

Conclusions

The present results suggest that neonatal VAS primes the response in girls such that they get a beneficial effect after a subsequent dose of VAS.

Trial Registration

Clinicaltrials.gov NCT00168597

The effect of high-dose vitamin A supplementation at birth on measles incidence during the first 12 months of life in boys and girls: an unplanned study within a randomised trial

Vitamin A treatment reduces mortality during acute measles infection, and vitamin A supplementation (VAS) to children above 6 months of age may reduce the incidence of measles infection. The effect of VAS at birth on measles incidence is unknown. In a randomised placebo-controlled trial in Guinea-Bissau, normal-birth-weight newborns were randomised to 50 000 IU (15 mg) VAS or placebo. During the trial, a measles epidemic occurred. We linked data from the trial with data from the measles infection surveillance and studied the effect of VAS on the measles incidence before 12 months of age in both sexes. A total of 165 measles cases were identified among the 4183 children followed from 28 d of age. Up to 6 months of age, the incidence rate ratio of measles for VAS compared with placebo was 0·54 (95 % CI 0·25, 1·15) among boys and 1·57 (95 % CI 0·80, 3·08) among girls (test of interaction, P = 0·04). The corresponding figures at 12 months were 0·67 (95 % CI 0·43, 1·05) and 1·17 (95 % CI 0·76, 1·79) (test of interaction, P = 0·08). VAS compared with placebo tended to be associated with less measles hospitalisation or death during the first 6 months of life in boys (P = 0·06), but not in girls. VAS at birth may affect the susceptibility to measles infection during the first 6 months of life in a sex-differential manner.

The effect of vitamin A supplementation and diphtheria-tetanus-pertussis vaccination on parasitaemia in an experimental murine malaria model

BACKGROUND

Vitamin A supplementation (VAS) decreases overall child mortality in low-income countries. For logistical reasons, VAS has been linked to routine childhood immunizations. However, several recent studies have indicated that VAS may increase mortality and morbidity from infectious diseases when given with the diphtheria-tetanus-pertussis (DTP) vaccine. The immunological effects of combining the 2 treatments are unknown.

METHODS

We studied the effect of treating C57BL/6 mice with VAS and DTP, 1 week prior to infection with Plasmodium berghei ANKA. The progression of disease was monitored through parasite load and time to death.

RESULTS

We found significantly higher levels of parasitaemia in VAS/DTP-treated mice than in control mice (crude geometric mean parasitaemia ratio 2.02 (1.08-3.76), p = 0.03). There was no effect of administering either VAS or DTP alone, indicating that the increase in parasitaemia was due to a synergistic effect of VAS and DTP (p for interaction = 0.02). The effect of VAS/DTP on levels of parasitaemia was modified by the specific parasite variant used. No effect was observed on time to death.

CONCLUSION

Our results indicate that VAS/DTP can negatively influence the outcome of malaria infection in mice, adding to the concerns about simultaneous VAS and DTP administration to children in low-income, malaria endemic countries.

Effect of revaccination with BCG in early childhood on mortality: randomised trial in Guinea-Bissau

OBJECTIVE

To determine whether BCG revaccination at 19 months of age reduces overall child mortality.

DESIGN

Randomised trial, with follow-up to age 5.

SETTING

A health project in Bissau, Guinea-Bissau, which maintains a health and demographic surveillance system in an urban area with 90 000 inhabitants.

PARTICIPANTS

2871 children aged 19 months to 5 years with low or no reactivity to tuberculin and who were not severely sick on the day of enrollment.

INTERVENTION

BCG vaccination or no vaccination (control).

MAIN OUTCOME MEASURE

Hazard ratios for mortality.

RESULTS

77 children died during follow-up. Compared with controls, the BCG revaccinated children had a hazard ratio of 1.20 (95% confidence interval 0.77 to 1.89). Two hundred and fifty children were admitted to hospital for the first time between enrollment and the end of the study, with an incidence rate ratio for BCG revaccinated children versus controls of 1.04 (0.81 to 1.33). The trial was stopped prematurely because of a cluster of deaths in the BCG arm of the study. This increase in mortality occurred at a time when many children had received missing vaccinations or vitamin A or iron supplementation; the hazard ratio for BCG revaccinated children compared with controls was 2.69 (1.05 to 6.88) in the period after these campaigns. Throughout the trial, the effect of BCG revaccination on mortality was significantly different (P=0.006) in children who had received diphtheria-tetanus-pertussis (DTP) booster vaccination before enrollment (hazard ratio 0.36, 0.13 to 0.99) and children who had not received the booster before enrollment (1.78, 1.04 to 3.04).

CONCLUSIONS

There was no overall beneficial effect of being revaccinated with BCG. The effect of BCG revaccination on mortality might depend on other health interventions. Trial registration Clinical Trials ICA4-CT-2002-10053-REVAC.

Vitamin A supplementation and BCG vaccination at birth in low birthweight neonates: two by two factorial randomised controlled trial

OBJECTIVE

To investigate the effect of vitamin A supplementation and BCG vaccination at birth in low birthweight neonates.

DESIGN

Randomised, placebo controlled, two by two factorial trial.

SETTING

Bissau, Guinea-Bissau.

PARTICIPANTS

1717 low birthweight neonates born at the national hospital.

INTERVENTION

Neonates who weighed less than 2.5 kg were randomly assigned to 25 000 IU vitamin A or placebo, as well as to early BCG vaccine or the usual late BCG vaccine, and were followed until age 12 months.

MAIN OUTCOME MEASURE

Mortality, calculated as mortality rate ratios (MRRs), after follow-up to 12 months of age for infants who received vitamin A supplementation compared with those who received placebo.

RESULTS

No interaction was observed between vitamin A supplementation and BCG vaccine allocation (P=0.73). Vitamin A supplementation at birth was not significantly associated with mortality: the MRR of vitamin A supplementation compared with placebo, controlled for randomisation to "early BCG" versus "no early BCG" was 1.08 (95% CI 0.79 to 1.47). Stratification by sex revealed a significant interaction between vitamin A supplementation and sex (P=0.046), the MRR of vitamin A supplementation being 0.74 (95% CI 0.45 to 1.22) in boys and 1.42 (95% CI 0.94 to 2.15) in girls. When these data were combined with data from a complementary trial among normal birthweight neonates in Guinea-Bissau, the combined estimate of the effect of neonatal vitamin A supplementation on mortality was 1.08 (95% CI 0.87 to 1.33); 0.80 (95% CI 0.58 to 1.10) in boys and 1.41 (95% CI 1.04 to 1.90) in girls (P=0.01 for interaction between neonatal vitamin A and sex).

CONCLUSIONS

The combined results of this trial and the complementary trial among normal birthweight neonates have now shown that, overall, it would not be beneficial to implement a neonatal vitamin A supplementation policy in Guinea-Bissau. Worryingly, the trials show that vitamin A supplementation at birth can be harmful in girls. Previous studies and future trials should investigate the possibility that vitamin A supplementation has sex differential effects. Trial registration ClinicalTrials.gov NCT00168610.

Does vitamin A supplementation interact with routine vaccinations? An analysis of the Ghana Vitamin A Supplementation Trial

BACKGROUND

The World Health Organization recommends vitamin A supplementation (VAS) at vaccination contacts after 6 mo of age to reduce mortality. However, it is unknown whether the effect of VAS is independent of vaccinations. One of the original VAS trials from Ghana had collected vaccination information.

OBJECTIVE

We reanalyzed the data to explore the hypothesis that VAS reduces mortality in children who had bacille Calmette-Guérin or measles vaccine as their most recent vaccine but increased mortality when diphtheria-tetanus-pertussis vaccine (DTP) was the most recent vaccine. On the basis of previous studies, we expected the effects to be strongest in girls.

DESIGN

At enrollment, children aged 6-90 mo were randomly assigned to receive VAS or placebo every 4 mo for 2 y. Vaccination status was assessed at enrollment and after 1 and 2 y by reviewing the children's health cards. Lack of a health card was presumed to mean that the child had not been vaccinated.

RESULTS

VAS had a beneficial effect only in children with no record of vaccination at enrollment (n = 5066); the mortality rate ratio (MRR) was 0.64 (95% CI: 0.47, 0.88) compared with 0.95 (95% CI: 0.72, 1.26) in children with one or more vaccinations (n = 6656). Among vaccinated children, the effect of VAS differed between boys (MRR: 0.74; 95% CI: 0.51, 1.08) and girls (MRR: 1.18; 95% CI: 0.84, 1.67) (P = 0.046 for interaction). VAS had a negative effect in measles-vaccinated girls who were missing one or more doses of DTP at enrollment, a group who often received DTP during follow-up (MRR: 2.60; 95% CI: 1.41, 4.80).

CONCLUSIONS

The effect of VAS differed by vaccination status. This is potentially problematic because VAS is provided at vaccination contacts.

Girls may have lower levels of maternal measles antibodies and higher risk of subclinical measles infection before the age of measles vaccination

BACKGROUND

Previous studies have suggested that girls may have lower maternal measles antibody levels than boys. Girls might therefore be more likely to contract measles infection before the normal age of measles vaccination at 9 months of age.

METHODS

In connection with a clinical trial of different measles vaccination strategies, we collected pre-measles vaccination blood samples at 4.5 months of age from two subgroups of children. Samples from these children were used to assess possible differences in maternal antibody levels for boys and girls. At 9 months of age another subgroup of children was sampled before the normal measles vaccination; these samples were used to assess the frequency of subclinical measles infection among boys and girls.

RESULTS

We determined measles-specific antibody levels for 812 children at 4.5 months of age and for 896 children at 9 months of age. At 4.5 months of age girls were less likely to have protective maternal antibody levels, the male-female ratio for protective antibody level being 1.23 (1.00-1.51). Among children sampled at 9 months of age, girls were more likely to have protective levels, the female-male ratio for having protective antibody levels being 1.65 (0.98-2.78) (p=0.054) and the geometric mean titre was significantly higher for girls (p=0.007). Children who lived in houses with known measles cases were more likely to have protective levels at 9 months of age even though they had not reported measles infection. Since we had excluded children with known measles infection, girls may have been more likely to have had subclinical measles infection. Combining clinical and possible subclinical measles infection, girls tended to be more likely than boys to contract measles infection before 9 months of age, the RR being 1.36 (0.97-1.90).

CONCLUSIONS

Girls lost maternal measles antibodies more rapidly than boys and well before 9 months of age. They may be more likely to contract subclinical measles infection before the current age of measles vaccination.

Effect of 50,000 IU vitamin A given with BCG vaccine on mortality in infants in Guinea-Bissau: randomised placebo controlled trial

OBJECTIVE

To investigate the effect of high dose vitamin A supplementation given with BCG vaccine at birth in an African setting with high infant mortality.

DESIGN

Randomised placebo controlled trial. Setting Bandim Health Project's demographic surveillance system in Guinea-Bissau, covering approximately 90,000 inhabitants. Participants 4345 infants due to receive BCG.

INTERVENTION

Infants were randomised to 50,000 IU vitamin A or placebo and followed until age 12 months.

MAIN OUTCOME MEASURE

Mortality rate ratios.

RESULTS

174 children died during follow-up (mortality=47/1000 person-years). Vitamin A supplementation was not significantly associated with mortality; the mortality rate ratio was 1.07 (95% confidence interval 0.79 to 1.44). The effect was 1.00 (0.65 to 1.56) during the first four months and 1.13 (0.75 to 1.68) from 4 to 12 months of age. The mortality rate ratio in boys was 0.84 (0.55 to 1.27) compared with 1.39 (0.90 to 2.14) in girls (P for interaction=0.10). An explorative analysis revealed a strong interaction between vitamin A and season of administration.

CONCLUSIONS

Vitamin A supplementation given with BCG vaccine at birth had no significant benefit in this African setting. Although little doubt exists that vitamin A supplementation reduces mortality in older children, a global recommendation of supplementation for all newborn infants may not contribute to better survival.

TRIAL REGISTRATION

Clinical trials NCT00168597.