BCG vaccination in low birth weight newborns: Analysis of lymphocyte proliferation, IL-2 generation and intradermal reaction to PPD

Abstract

Objective: To study vaccinal scar formation and post-vaccinal immune response in newborns with birth weight ranging from 2000 to 2499 g vaccinated in the first week of life with intradermal bacille Calmette-Guérin (BCG) (Moreau-Rio de Janeiro strain). Method: Specific immune response to PPD was assessed in 30 low birth weight newborns (mean birth weight = 2311.7 ± 122.1 g; mean gestational age = 38.1 ± 1.8 weeks) in comparison to 56 control infants (mean birth weight = 3198.9 ± 267.2 g; mean gestational age = 38.5 ± 1.2 weeks). Results: Low birth weight infants have an efficient immune response to vaccinal stimulus when compared to control infants as judged by specific in vitro lymphocyte proliferation (mean SI = 9.7 ± 12.9 vs SI = 8.8 ± 10.0, P = 0.72) and IL-2 production (mean SI = 3.1 ± 3.4 vs SI = 2.6 ± 2.0, P = 0.38). Intradermal reaction to PPD was also comparable in both groups (mean induration diameter = 9.5 ± 5.1 mm vs 9.6 ± 5.0 mm, P = 0.94). Conclusion: These data suggest that low birth weight newborns show a good immune response to BCG, thus reinforcing the inclusion of such infants in regular vaccination programs with intradermal BCG.