BCG revaccination in school children: evolution of the lesion at the vaccination site between 48 hours and 10 weeks

Abstract

Cutaneous reaction after BCG revaccination has been cause of concerns due its magnitude. Would it be intense enough to discourage its use in school-age children? The objective of this study is to describe the evolution of BCG vaccination site between 48 hours and 10 weeks post-revaccination. A descriptive cohort study was carried out involving 484 children between six and 11 years. The subjects were vaccinated with 0.1 mL of BCG-Moreau. Erythema, induration, pustule, ulcer, crust and final scar were measured within 48 h, 72 h and weekly until the tenth week, evaluated between July and December 1987. Epi Info 6.0 software was utilized to analyze frequencies, means, median and standard deviations. Induration was present in 99.1% and erythema in 91.6% of 438 children evaluated within 48 h. Pustules were observed in the first week in 26.1% of 479 children. The first ulcers were seen during the second week. In the tenth week, 69.8% of 463 children showed crusts but only 29.2% completed the healing process. BCG revaccination in school-age children causes intense and early reaction that can be related to Koch phenomenon, even though it does not present the expected reduction in the healing period. The magnitude of the reaction is not enough to discourage its recommendation for school-age children. On the other hand, it is possible that the rapid inflammatory response is an indication of active immune response from the first vaccination.