BCG vaccination of full-term infants with chronic intrauterine malnutrition: influence of immunization age on development of post-vaccination, delayed tuberculin hypersensitivity.

To determine the effect of intrauterine growth retardation (IUGR) on the response to BCG vaccination, we evaluated the specific delayed tuberculin hypersensitivity of 57 full-term infants with symmetric IUGR (SGA or small for gestational age) and 52 full-term infants with normal intrauterine growth (AGA or appropriate for gestational age). The infants were evaluated using post-vaccination skin tests to tuberculin purified protein derivative (PPD) and tuberculin lymphocyte transformation tests. Using a positive response to the skin test as an indicator of delayed hypersensitivity, we found that the rate of response to BCG in the SGA and AGA groups was similar. A total of 65% of infants with IUGR responded to BCG vaccination. The response rate among SGA infants who were vaccinated at 5 days of age, about 26 days of age (weight > or = 2500 g), 3 months of age, and 6 months of age was 68%, 47%, 69%, and 88%, respectively. The overall response rate for infants with no IUGR was 71%; the rate response to BCG vaccination among this group was 52% (those vaccinated at 5 days of age), 90% (3 months of age), and 80% (6 months of age). Our data suggest that the immunogenicity of BCG vaccine is similar in term infants who have normal or abnormal intrauterine growth and the presence of IUGR should not be a reason for delaying BCG vaccination.