Long lasting BCG protection against leprosy

Abstract

Background: BCG vaccine protects against leprosy. Objectives: Estimate BCG protection against leprosy by age by age. Methods: A case control study with 226 cases of leprosy and 857 controls. BCG vaccination was ascertained via examination of BCG scars. Protection is presented for three age groups. Results: BCG protection against leprosy was 86% (95% CI: 77–92%) in the age group 18–29; 54% (95% CI: −37% to 85%) in the age group 30–39 and 32% (95% CI: −3% to 56%) in those aged 40 or more. Conclusions: BCG efficacy against leprosy may well last for three decades and possibly even longer. BCG vaccination must have contributed to worldwide reduction in leprosy incidence.