Complement component 3: a new paradigm in tuberculosis vaccine.

Vaccines are critical for the control of tuberculosis (TB) affecting humans and animals worldwide. First-generation vaccines protect from active TB but new vaccines are required to protect against pulmonary disease and infection. Recent advances in post-genomics technologies have allowed the characterization of host-pathogen interactions to discover new protective antigens and mechanisms to develop more effective vaccines against TB. Studies in the wild boar model resulted in the identification of complement component 3 (C3) as a natural correlate of protection against TB. Oral immunization with heat-inactivated mycobacteria protected wild boar against TB and showed that C3 plays a central role in protection. These results point at C3 as a target to develop novel vaccine formulations for more effective protection against TB in humans and animals.