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.


METHODS
Randomised trial, with follow-up to age 5.


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


METHODS
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.


METHODS
BCG vaccination or no vaccination (control).


METHODS
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.
Bandim Health Project, Indepth Network, Apartado 861, Bissau, Guinea-Bissau.
Adam Edvin
AE
Roth
Christine Stabell
CS
Benn
Henrik
H
Ravn
Amabelia
A
Rodrigues
Ida Maria
IM
Lisse
Maria
M
Yazdanbakhsh
Hilton
H
Whittle
Peter
P
Aaby
D000276:Adjuvants, Immunologic / Q000008:administration & dosage*; D001500:BCG Vaccine / Q000008:administration & dosage*; D046688:Child Mortality; D002675:Child, Preschool; D005260:Female; D006169:Guinea-Bissau; D006801:Humans; D007117:Immunization, Secondary / Q000401:mortality*; D007223:Infant; D008297:Male; D016896:Treatment Outcome; D014376:Tuberculosis / Q000401:mortality* / Q000517:prevention & control; D014504:Urban Health
D000276:Adjuvants, Immunologic; D001500:BCG Vaccine