Effect of revaccination with BCG in early childhood on mortality: randomised trial in Guinea-Bissau
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.
Trial registration Clinical Trials ICA4-CT-2002-10053-REVAC.
Edited from bmj.com
Picture from telegraph.co.uk
#revaccination #bcg