| 1. |
- Roth, Adam, et al.
(författare)
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Effect of revaccination with BCG in early childhood on mortality: randomised trial in Guinea-Bissau
- 2010
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Ingår i: BMJ: British Medical Journal. - : BMJ. - 1756-1833. ; 340
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Tidskriftsartikel (refereegranskat)abstract
- 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 enrolment. 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 enrolment 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 enrolment (hazard ratio 0.36, 0.13 to 0.99) and children who had not received the booster before enrolment (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.
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| 2. |
- Benn, Christine Stabell, et al.
(författare)
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Vitamin A supplementation and BCG vaccination at birth in low birthweight neonates: two by two factorial randomised controlled trial
- 2010
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Ingår i: BMJ: British Medical Journal. - : BMJ. - 1756-1833. ; 340
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 3. |
- Sartono, Erliyani, et al.
(författare)
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Oral Polio Vaccine Influences the Immune Response to BCG Vaccination. A Natural Experiment
- 2010
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- Background: Oral polio vaccine (OPV) is recommended to be given at birth together with BCG vaccine. While we were conducting two trials including low-birth-weight (LBW) and normal-birth-weight (NBW) infants in Guinea-Bissau, OPV was not available during some periods and therefore some infants did not receive OPV at birth, but only BCG. We investigated the effect of OPV given simultaneously with BCG at birth on the immune response to BCG vaccine. Methods and Findings: We compared the in vitro and the in vivo response to PPD in the infants who received OPV and BCG with that of infants who received BCG only. At age 6 weeks, the in vitro cytokine response to purified protein derivate (PPD) of M. Tuberculosis was reduced in LBW and NBW infants who had received OPV with BCG. In a pooled analysis receiving OPV with BCG at birth was associated with significantly lower IL-13 (p = 0.041) and IFN-gamma (p = 0.004) and a tendency for lower IL-10 (p = 0.054) in response to PPD. Furthermore, OPV was associated with reduced in vivo response to PPD at age 2 months, the prevalence ratio (PR) of having a PPD reaction being 0.75 (0.58-0.98), p = 0.033, and with a tendency for reduced likelihood of having a BCG scar (0.95 (0.91-1.00), p = 0.057)). Among children with a scar, OPV was associated with reduced scar size, the regression coefficient being -0.24 (-0.43-0.05), p = 0.012. Conclusions: This study is the first to address the consequences for the immune response to BCG of simultaneous administration with OPV. Worryingly, the results indicate that the common practice in low-income countries of administering OPV together with BCG at birth may down-regulate the response to BCG vaccine.
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