rBCG30 (recombinant Bacillus Calmette-Guérin 30) is a prospective Bacillus Calmette-Guérin vaccine against tuberculosis. It is a live vaccine, consisting of BCG, which has been evaluated as a tuberculosis vaccination. It is genetically modified to produce abundant amounts of mycolyl transferase, a 30 antigen (Antigen 85B) that has been shown to produce a strong immune response in animals and humans. rBCG30 had been in human clinical trials, but no clinical development has been reported since 2007.
Trials with rBCG30 were halted as the vaccine contained an antibiotic resistance gene. A new version of the vaccine without the antibiotic resistance marker was created. This new version of the vaccine, rBCG30-ARMF-II, often called rBCG30, also expresses 2.6 fold more Ag85B than the original vaccine.
The vaccine completed a Phase I double-blind randomized controlled clinical trial that demonstrated that rBCG30 was safe and immunogenic; during nine months of follow-up, rBCG30, but not BCG, induced significantly increased Antigen 85B-specific immune responses in eight immunological assays (blood lymphocyte proliferation, antibody responses by ELISA, interferon-gamma producing CD4+ and CD8+ T cells ex vivo, central memory CD4+ and CD8+ T cells, interferon-gamma ELISPOT responses, and the capacity of T cells to activate macrophages to inhibit mycobacterial intracellular multiplication). An additional animal study found that rBCG30 also helps protect against Mycobacterium leprae, the bacteria that causes leprosy. Disrupting IL10/STAT3 signaling during vaccination through small molecules enhances vaccination efficacy.