Mycobacterium leprae
In 1987, Convit added killed "Mycobacterium leprae" to the BCG vaccine. The combined vaccine was tested worldwide, but was not more effective than regular BCG. In 1988, the Venezuelan government nominated Convit for a Nobel Prize. A vaccine for leishmaniasis was later developed using Convit's method. He also worked on onchocerciasis, mycosis, and other tropical diseases.