Setting: Child welfare division of a university-based department of pediatrics in Turkey.
Objective: To determine specific IgM and IgG response after BCG vaccination.
Design: Prospective, randomized trial.
Methods: Serum samples of 66 infants were taken before and at 2, 4, 6 and 15 months after vaccination. 35 infants were vaccinated at the first month and 31 at the second month after delivery. An ELISA assay was performed using PPD antigen.
Results: IgM antibodies increased significantly (P < 0.05) during the post-vaccination period. On the other hand IgG antibodies decreased in the second month after vaccination. At the fourth month the IgG level began to rise continuously (P < 0.01). The infants who were vaccinated at the second month showed a higher IgM response at the second and fourth month than those vaccinated in the first month (P < 0.05), but the difference was not visible thereafter (P > 0.05). 52 infants (78%) were tuberculin positive 8 weeks after vaccination.
Conclusion: Anti-PPD IgM and IgG levels rise progressively in BCG-vaccinated infants.