Safety and effectiveness of BCG vaccination in preterm babies.

Aim: To assess the cell mediated immune response to BCG vaccine in preterm babies.

Methods: Sixty two consecutive preterm babies born at < 35 weeks of gestation were randomly allocated into two groups. Babies in group A were vaccinated early at 34-35 weeks and group B were vaccinated late at 38-40 weeks of postconceptional age. The two groups were similar in terms of: gestational age (mean (SD) 33.1 (1. 1) and 33 (1.2) weeks, respectively); birthweight 1583 (204) and 1546 (218) g; neonatal problems; socioeconomic status; and postnatal weight gain. The cell mediated immune response to BCG was assessed using the Mantoux test and the lymphocyte migration inhibition test (LMIT) 6-8 weeks after BCG vaccination. Induration of >5 mm after the Mantoux test was taken as a positive response.

Results: There was no significant difference in the tuberculin conversion rates (80% and 80.7%, respectively), positive LMIT (86.6% and 90.3%, respectively), or BCG scar (90.0% and 87.1%, respectively) among the two groups.

Conclusions: Prematurity seems to be an unlikely cause for poor vaccine uptake. Preterm babies can be effectively vaccinated with BCG at 34-35 weeks of postconceptional age, the normal time of discharge in a developing country.