Neonatal vitamin A supplementation associated with a cluster of deaths and poor early growth in a randomised trial among low-birth-weight boys of vitamin A versus oral polio vaccine at birth.

BACKGROUND: The effect of oral polio vaccine administered already at birth (OPV0) on child survival was not examined before being recommended in 1985. Observational data suggested that OPV0 was harmful for boys, and trials have shown that neonatal vitamin A supplementation (NVAS) at birth may be beneficial for boys. We set out to test this research question in a randomised trial. METHODS: The trial was carried out at the Bandim Health Project, Guinea-Bissau. We planned to enrol 900 low-birth weight (LBW) boys in a randomised trial to investigate whether NVAS instead of OPV0 could lower infant mortality for LBW boys. At birth, the children were randomised to OPV (usual treatment) or VAS (intervention treatment) and followed for 6 months for growth and 12 months for survival. Hazard Ratios (HR) for mortality were calculated using Cox regression. We compared the individual anthropometry measurements to the 2006 WHO growth reference. We compared differences in z-scores by linear regression. Relative risks (RR) of being stunted or underweight were calculated in Poisson regression models with robust standard errors. RESULTS: In the rainy season we detected a cluster of deaths in the VAS group and the trial was halted immediately with 232 boys enrolled. The VAS group had significantly higher mortality than the OPV0 group in the rainy season (HR: 9.91 (1.23 - 80)). All deaths had had contact with the neonatal nursery; of seven VAS boys enrolled during one week in September, six died within two months of age, whereas only one died among the six boys receiving OPV (p = 0.05). Growth (weight and arm-circumference) in the VAS group was significantly worse until age 3 months. CONCLUSION: VAS at birth instead of OPV was not beneficial for the LBW boys in this study. With the premature closure of the trial it was not possible to answer the research question. However, the results of this study call for extra caution when testing the effect of NVAS in the future. TRIAL REGISTRATION: http://www.clinicaltrials.gov NCT00625482. Registered 18 February 2008.

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.

SNP may modify the effect of vitamin A supplementation at birth on cytokine production in a whole blood culture assay.

Within a neonatal vitamin A supplementation (VAS) trial, we investigated the effect of VAS on TNF-α, IL-10, IL-5 and IL-13 production after lipopolysaccharide, purified protein derivative (PPD) of Mycobacterium tuberculosis and phytohaemagglutinin stimulation using a whole blood culture protocol. We found that VAS recipients had lower unstimulated TNF-α concentrations than placebo recipients. In the present paper, we investigated whether the SNP TNF-α - 308, TNF-α - 238, IL-10 - 592, IL-10 - 1082 and toll-like receptor 4 (TLR4)+896 modified the effect of VAS on cytokine production. DNA and cytokine concentrations were available from 291 children. We found a significant interaction between TNF-α - 308 genotype and VAS for the unstimulated TNF-α production (Pinteraction = 0·04); among G homozygotes, TNF-α concentrations were significantly lower after VAS compared with placebo, whereas for A carriers, VAS did not appear to have any effect. For TNF-α - 238, there was a tendency towards an increase in PPD-stimulated TNF-α production after VAS for the G homozygotes, but the opposite tendency for A allele carriers (Pinteraction = 0·07). Stratification by sex revealed a significant VAS-genotype interaction for boys for TNF-α - 238. There was a borderline-significant three-way interaction (P = 0·05) between sex, VAS and TLR4+896 genotype. Although the present study had very limited representation of the genetic variation with potential for modification of the response to VAS, it adds to the efforts of untangling the diverse effects and impact of VAS.

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.

Should infant girls receive micronutrient supplements?

BACKGROUND: We have proposed the hypothesis that the combination of vitamin A supplementation and diphtheria-tetanus-pertussis (DTP) vaccination may be associated with increased mortality in girls. Recent zinc/folic acid (FA) and iron supplementation trials did not find any beneficial effects on mortality. We reviewed the studies for evidence of a negative interaction between zinc/folic acid/iron and DTP vaccination in girls. METHODS: Based on the published papers, we calculated age- and sex-specific mortality estimates. No vaccination status data were provided. RESULTS: Both zinc/FA and iron seemed to have a sex- and age-differential effect, the effect being less beneficial in the youngest girls who are most likely to have DTP vaccine as their most recent vaccination. CONCLUSIONS: Like vitamin A, zinc/FA and iron may not benefit the youngest girls. The question is whether this is inherent in girls or due to an interaction with some environmental factor like DTP.