Single dose vaccination was carried out with Mycobacterium habana
vaccine, 31
lepromatous leprosy cases receiving 1.5 mg (1.5 mg = 6.27 x 10(8) bacilli) and 36 household contacts randomly receiving 1.5, 2.0, 2.5 mg
vaccine intradermally. Duration of study was 18 weeks. Vaccination induced
lepromin conversion in 100% of
lepromatous leprosy cases and
lepromin negative household contacts and augmentation of
lepromin reactivity in 100% of
lepromin positive household contacts, which was stable for the 15 weeks duration of follow-up. The maximum augmentation in
lepromin reactivity was obtained with 1.5 mg of
vaccine, which is probably the supramaximal dose. Overall, post-vaccination, those without prior BCG vaccination
scars showed higher mean values of
lepromin augmentation. Local vaccination site changes included induration, ulceration,
itching,
pain and uncomplicated regional
lymphadenopathy, all of which remitted spontaneously by 15 weeks. Systemic side-effects noted were
pyrexia, ENL and
jaundice, and were seen with no greater frequency than that reported in other
vaccine trials. Overall, systemic side-effects were easily controlled and were not accompanied by clinically detectable nerve or ocular damage. The safety profile investigations revealed an increase in the mean values of Hb%, RBC count and PCV in household contacts and of PCV in lepromatous patients, post-vaccination. Alterations in the liver function tests were also observed in patients of
lepromatous leprosy. Thus, M. habana
vaccine appears to be useful in stimulating specific CMI against M. leprae as evidenced by increased
lepromin reactivity.