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

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.

Micronutrient Supplementation and Fortification Interventions on Health and Development Outcomes among Children Under-Five in Low- and Middle-Income Countries: A Systematic Review and Meta-Analysis

Micronutrient deficiencies continue to be widespread among children under-five in low- and middle-income countries (LMICs), despite the fact that several effective strategies now exist to prevent them. This kind of malnutrition can have several immediate and long-term consequences, including stunted growth, a higher risk of acquiring infections, and poor development outcomes, all of which may lead to a child not achieving his or her full potential. This review systematically synthesizes the available evidence on the strategies used to prevent micronutrient malnutrition among children under-five in LMICs, including single and multiple micronutrient (MMN) supplementation, lipid-based nutrient supplementation (LNS), targeted and large-scale fortification, and point-of-use-fortification with micronutrient powders (MNPs). We searched relevant databases and grey literature, retrieving 35,924 papers. After application of eligibility criteria, we included 197 unique studies. Of note, we examined the efficacy and effectiveness of interventions. We found that certain outcomes, such as anemia, responded to several intervention types. The risk of anemia was reduced with iron alone, iron-folic acid, MMN supplementation, MNPs, targeted fortification, and large-scale fortification. Stunting and underweight, however, were improved only among children who were provided with LNS, though MMN supplementation also slightly increased length-for-age z-scores. Vitamin A supplementation likely reduced all-cause mortality, while zinc supplementation decreased the incidence of diarrhea. Importantly, many effects of LNS and MNPs held when pooling data from effectiveness studies. Taken together, this evidence further supports the importance of these strategies for reducing the burden of micronutrient malnutrition in children. Population and context should be considered when selecting one or more appropriate interventions for programming.

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.

Vitamin A supplementation for the prevention of morbidity and mortality in infants one to six months of age

BACKGROUND

Vitamin A deficiency is a significant public health problem in low- and middle-income countries. Vitamin A supplementation provided to infants less than six months of age is one of the strategies to improve the nutrition of infants at high risk of vitamin A deficiency and thus potentially reduce their mortality and morbidity.

OBJECTIVES

To evaluate the effect of synthetic vitamin A supplementation in infants one to six months of age in low- and middle-income countries, irrespective of maternal antenatal or postnatal vitamin A supplementation status, on mortality, morbidity and adverse effects.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 2), MEDLINE via PubMed (1966 to 5 March 2016), Embase (1980 to 5 March 2016) and CINAHL (1982 to 5 March 2016). We also searched clinical trials databases, conference proceedings and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised or quasi-randomised, individually or cluster randomised trials involving synthetic vitamin A supplementation compared to placebo or no intervention provided to infants one to six months of age were eligible.

DATA COLLECTION AND ANALYSIS

Two review authors assessed the studies for eligibility and assessed their risk of bias and collected data on outcomes.

MAIN RESULTS

The review included 12 studies (reported in 22 publications). The included studies assigned 24,846 participants aged one to six months to vitamin A supplementation or control group. There was no effect of vitamin A supplementation for the primary outcome of all-cause mortality based on seven studies that included 21,339 (85%) participants (risk ratio (RR) 1.05, 95% confidence interval (CI) 0.89 to 1.25; I2 = 0%; test for heterogeneity: P = 0.79; quality of evidence: moderate). Also, there was no effect of vitamin A supplementation on mortality or morbidity due to diarrhoea and respiratory tract infection. There was an increased risk of bulging fontanelle within 24 to 72 hours of supplementation in the vitamin A group compared to control (RR 3.10, 95% CI 1.89 to 5.09; I2 = 9%, test for heterogeneity: P = 0.36; quality of evidence: high). There was no reported subsequent increased risk of death, convulsions or irritability in infants who developed bulging fontanelle after vitamin A supplementation, and it resolved in most cases within 72 hours. There was no increased risk of other adverse effects such as vomiting, irritability, diarrhoea, fever and convulsions in the vitamin A supplementation group compared to control. Vitamin A supplementation did not have any statistically significant effect on vitamin A deficiency (RR 0.86, 95% CI 0.70 to 1.06; I2 = 27%; test for heterogeneity: P = 0.25; quality of evidence: moderate).

AUTHORS' CONCLUSIONS

There is no convincing evidence that vitamin A supplementation for infants one to six months of age results in a reduction in infant mortality or morbidity in low- and middle-income countries. There is an increased risk of bulging fontanelle with vitamin A supplementation in this age group; however, there were no reported subsequent complications because of this adverse effect.

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.

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.

Heterologous and sex differential effects of administering vitamin A supplementation with vaccines

WHO recommends high-dose vitamin A supplementation (VAS) to children from 6 months to 5 years of age in low-income countries, in order to prevent and treat vitamin A deficiency-associated morbidity and mortality. The current policy does not discriminate this recommendation either by sex or vaccination status of the child. There is accumulating evidence that the effects of VAS on morbidity, mortality and immunological parameters depend on concomitant vaccination status. Moreover, these interactions may manifest differently in males and females. Certain vaccines administered through the Expanded Program on Immunization have been shown to alter all-cause mortality from infections other than the vaccine-targeted disease. This review summarizes the evidence from observational studies and randomized-controlled trials of the effects of VAS on these so-called heterologous or non-specific effects of vaccines, with a focus on sex differences. In general, VAS seems to enhance the heterologous effects of vaccines, particularly for diphtheria-tetanus-pertussis and live measles vaccines, where some studies, although not unanimously, show a stronger interaction between VAS and vaccination in females. We suggest that vaccination status and sex should be considered when evaluating the effects of VAS in early life.

The effect of newborn vitamin A supplementation on infant immune functions: trial design, interventions, and baseline data

In recent years, neonatal vitamin A supplementation is considered as an essential infant-survival intervention but the evidence is not conclusive. This randomized controlled clinical trial was conducted to evaluate the effect of vitamin A on immune competence in early infancy. Results would provide a mechanistic basis for understanding the effect of this intervention on infant survival. Within 2 days of birth, infants born at one maternity clinic located in a poor slum area of Dhaka city were supplemented with either 50,000 IU vitamin A or placebo. Live attenuated oral polio vaccine (OPV) and BCG vaccine were provided after supplementation. Infants also receive diphtheria, pertussis, tetanus (TT), hepatitis B (HBV) and Haemophilus influenzae B vaccines (pentavalent combination) along with OPV at 6, 10 and 14 weeks of age. Infant thymus size, anthropometry, feeding practice and morbidity data were collected at regular interval. Infant blood samples were collected to determine T-cell-receptor excision circle (TREC), total, naïve and memory T cells and mucosal targeting lymphocytes including Treg cells. TT-, HBV-, BCG- and OPV-specific T cell blastogenic, cytokine and plasma cell antibody responses were also measured. In 16 mo enrollment period, 306 newborns, equal number of boys and girls, were enrolled. ~95% completed the 4-month follow-up period. Baseline characteristics are presented here. Anthropometry and immune assays with fresh blood samples were completed immediately while stored samples were analyzed in single batches at the end of the trial. Connecting different aspects of immunological data in early infancy will help elucidate immune competence for protecting infection. Trial registration ClinicalTrials.gov: NCT01583972.

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.

Interaction between neonatal vitamin A supplementation and timing of measles vaccination: a retrospective analysis of three randomized trials from Guinea-Bissau

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Early measles vaccine and neonatal vitamin A supplementation may become policy in low-income countries.

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Vaccines and vitamin A may interact.

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In children who received early measles vaccine, neonatal vitamin A was associated with 5-fold higher overall mortality.

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Implementation of both policies at the same time may lead to increased child mortality.

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Co-packaging of child health interventions should be investigated for the effect on overall mortality.

Background

In Guinea-Bissau we conducted three trials of neonatal vitamin A supplementation (NVAS) from 2002 to 2008. None of the trials found a beneficial effect on mortality. From 2003 to 2007, an early measles vaccine (MV) trial was ongoing, randomizing children 1:2 to early MV at 4.5 months or no early MV, in addition to the usual MV at 9 months. We have previously found interactions between vitamin A and vaccines.

Objective

We investigated whether there were interactions between NVAS and early MV.

Design

We compared the mortality of NVAS and placebo recipients: first, from 4.5 to 8 months for children randomized to early MV or no early MV; and second, from 9 to 17 months in children who had received two MV or one MV. Mortality rates (MR) were compared in Cox models producing mortality rate ratios (MRR).

Results

A total of 5141 children were randomized to NVAS (N = 3015) or placebo (N = 2126) and were later randomized to early MV (N = 1700) or no early MV (N = 3441). Between 4.5 and 8 months, NVAS compared with placebo was associated with higher mortality in early MV recipients (MR = 30 versus MR = 0, p = 0.01), but not in children who did not receive early MV (p for interaction between NVAS and early MV = 0.03). From 9 to 17 months NVAS was not associated with mortality. Overall, from 4.5 to 17 months NVAS was associated with increased mortality in early MV recipients (Mortality rate ratio = 5.39 (95% confidence interval: 1.62, 17.99)).

Conclusions

These observations indicate that NVAS may interact with vaccines given several months later. This may have implications for the planning of future child intervention programs.

A randomized trial of a standard dose of Edmonston-Zagreb measles vaccine given at 4.5 months of age: effect on total hospital admissions

Observational studies and trials from low-income countries indicate that measles vaccine has beneficial nonspecific effects, protecting against non-measles-related mortality. It is not known whether measles vaccine protects against hospital admissions. Between 2003 and 2007, 6417 children who had received the third dose of diphtheria, tetanus, and pertussis vaccine were randomly assigned to receive measles vaccine at 4.5 months or no measles vaccine; all children were offered measles vaccine at 9 months of age. Using hospital admission data from the national pediatric ward in Bissau, Guinea-Bissau, we compared admission rates between enrollment and the 9-month vaccination in Cox models, providing admission hazard rate ratios (HRRs) for measles vaccine versus no measles vaccine. All analyses were conducted stratified by sex and reception of neonatal vitamin A supplementation (NVAS). Before enrollment the 2 groups had similar admission rates. Following enrollment, the measles vaccine group had an admission HRR of 0.70 (95% confidence interval [CI], .52-.95), with a ratio of 0.53 (95% CI, .32-.86) for girls and 0.86 (95% CI, .58-1.26) for boys. For children who had not received NVAS, the admission HRR was 0.53 (95% CI, .34-.84), with an effect of 0.30 (95% CI, .13-.70) for girls and 0.73 (95% CI, .42-1.28) for boys (P = .08, interaction test). The reduction in admissions was separately significant for measles infection (admission HRR, 0 [95% CI, 0-.24]) and respiratory infections (admission HRR, 0.37 [95% CI, .16-.89]). Early measles vaccine may have major benefits for infant morbidity patterns and healthcare costs. Clinical trials registration NCT00168558.

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.

Vitamin A supply to mothers and children: challenges and opportunities

PURPOSE OF REVIEW

Although we are close to the centennial of the discovery of vitamin A, our understanding of the functions of this major micronutrient is still evolving. Given its major role in fetal development, growth, vision, immunity and survival, a subtle balance is required between adequate intake to avoid deficiency and excessive intake to avoid toxicity, both in low income and industrialized countries.

RECENT FINDINGS

This review highlights the potential impact of vitamin A supplementation (VAS) in mothers and children suffering from vitamin A deficiency (VAD) on mortality and morbidities, and warns against the increasingly frequent use of bariatric surgery especially to treat severely obese childbearing women, which is known to alter vitamin A status.

SUMMARY

Despite massive vitamin A supplementation public health policies in developing countries, the burden of VAD is still common and efforts should be maintained to better target populations at risk, and to develop alternative strategies for supplementation based on sustainable and integrated approaches. In industrialized countries, VAD due to insufficient intake is scarce, but it may surprisingly occur due to the decreased absorption of lipids following antiobesity treatments. Specific approaches should be developed to better monitor and supplement obese childbearing women who have undergone bariatric surgery.

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.

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