Protective effects of BCG vaccination against multibacillary disease, reactions, and disabilities in childhood leprosy: Insights from a retrospective observational study from a tertiary care center in India.

Background And Methods: While leprosy primarily affects adults, childhood leprosy poses unique challenges because of its potential to cause lifelong disabilities and stigma. This is a retrospective record review of all patients aged 15 or below, diagnosed with leprosy, who were registered at the leprosy clinic of our tertiary care center from June 2014 to December 2023.

Results: As per hospital records, 1083 leprosy cases were registered at our center during the study period. Of these, 50 (4.6%) were children below 15 years of age. Persistent skin lesions (PSL) were seen in 11 (22%) cases, and the most common spectrum in which PSL were seen was the bordeline tuberculoid spectrum (BT) (7/11; 63.6%). Among these cases, a Bacillus Calmette-Guerin (BCG) scar was present in only four (36.4%) patients. Overall, a BCG scar was noted in 39/50 cases (78%). The relationship between having no BCG scar and multibacillary disease, lepromatous leprosy (LL), or the borderline lepromatous (BL) spectrum was statistically significant (P = 0.021). Of the six reaction cases, only one patient had a BCG scar (2%). A statistically significant association was found between the absence of a BCG scar and having a reaction (P < 0.01). Of the 11 grade 2 disability cases, nine cases (all within the BL or LL spectrum) had no BCG scar, which was also statistically significant (P < 0.01).

Conclusions: Further research is warranted to strengthen the evidence of the impact of vaccination [BCG/Mycobacterium indicus pranii (MIP)] on the patterns of childhood leprosy, its effect on PSL, and its role in the prevention of reactions and disabilities. Such research would also help in optimizing strategies for the vaccine's universal application.