Effectiveness of BCG vaccination among leprosy contacts: a cohort study

Abstract

The study assessed the effectiveness of BCG vaccination against leprosy among the contacts of 1161 leprosy patients at the FIOCRUZ Leprosy Outpatient Clinic, RJ, Brazil, from June 1987 to December 2006. Following National Leprosy Program guidelines, the clinic has administered one-to-two doses to all healthy contacts since 1991. Among the 5680 contacts, 304 (5.4%) already had leprosy. Of the 5376 eligible healthy contacts, 3536 were vaccinated, 30 of whom were excluded due to previous or current tuberculosis, or HIV. In 18 years of follow up, 122 (2.15%) incident cases were diagnosed (58 vaccinated and 64 not), 28 occurring in the first year of follow up (21 vaccinated, 16 with no scar). The protection conferred by BCG was 56% and was not substantially affected by previous BCG vaccination (50% with a scar and 59% without). The risk of tuberculoid leprosy during the initial months was high among those vaccinated with no scar. However, it had substantially declined by the first year and in the following years, when the protection rate in this group reached 80%. Since Brazil is endemic for leprosy and the detection rate is not declining satisfactorily, vaccinating all contacts could be an effective means of substantially reducing the incidence of leprosy.

Leprosy exposure, infection and disease: a 25-year surveillance study of leprosy patient contacts

“…Among the studies from Fiocruz cohort, one case-control study (Alvim 1993) confirmed the protective role of BCG. Duppre 2008 andDuppre et al (2008) found that the effectiveness of BCG vaccination is related to age; its protective effect is stronger during the first years of life. The study also demonstrated that contact re-vaccination (in contacts with a BCG scar) confers additional protection.…”

The potential for vaccination in leprosy elimination: new tools for targeted interventions

“…Computer modelling based on the 2003 leprosy status in the districts of Nilphamari and Rangpur, Bangladesh, indicated that leprosy incidence would be substantially reduced by effective BCG vaccine coverage of infants and the combined strategies of contact tracing, early diagnosis and treatment of infection and/or chemoprophylaxis among HHC (Fischer et al 2011). Models including a second BCG vaccination were not generated and the efficacy of this approach has been debated (Setia et al 2006, Duppre et al 2008, van Brakel et al 2010.…”

Vaccination with the ML0276 Antigen Reduces Local Inflammation but Not Bacterial Burden during Experimental M ycobacterium leprae Infection

“…It is common practice in some countries, however, to reimmunize leprosy patients and their close contacts with BCG, even though the efficacy of this BCG reimmunization regimen is debated (17,18,57). In addition, direct injection of IL-2 and IFN-␥ into leprosy lesions does not induce type 1 reactions, although prolonged intradermal IFN-␥ treatment of LL patients does increase the risk of type 2 reactions (erythema nodosum leprosum) (33,55).…”