Preclinical studies show different versions of a TB vaccine under development at Texas Biomed are safe and effective, moving the candidate vaccine a step closer towards clinical trials.
SAN ANTONIO (Sept. 18, 2025) – A tuberculosis vaccine under development at Texas Biomedical Research Institute is making headway towards human clinical trials. A preclinical study demonstrated that different variations of the vaccine are safe and effective at protecting against tuberculosis (TB).
The study was recently published in JCI Insight and builds on results reported earlier this year.
Texas Biomed Professor Deepak Kaushal, Ph.D., is developing a live attenuated TB vaccine, which involves a weakened form of Mycobacterium tuberculosis (Mtb), the bacteria that causes TB. The vaccine candidate is called delta sigH because the gene that codes for the protein sigma H has been removed. This modification ensures the bacteria cannot survive in the lungs and cause disease.
However, international standards, set out in the 2005 Geneva Consensus, call for at least two genes to be knocked out before a live attenuated TB vaccine can be tested in people.
“Knocking out at least two genes provides an extra layer of safety,” Dr. Kaushal explained. “We’re finding multiple ways to block the bacteria from operating normally so that once it is introduced into the body as part of a vaccine, it is harmless and only helps generate a protective immune response.”
Dr. Kaushal and his team evaluated eight vaccine variations – with either two or three genes knocked out – in nonhuman primates, the gold standard for understanding how an entire immune system will react to a medicine, vaccine or therapy. The animal models represented healthy patients exposed to TB and those that are immunocompromised by having both HIV and TB. None of the animals developed TB disease after receiving the vaccines.
“Demonstrating these double and triple knock-out variations are safe is an important milestone for us to meet as we move the delta sigH vaccine through the development process,” Dr. Kaushal said.
The next step is to determine which knock-out combination is the most effective.
“I am extremely proud of my lab for all the hard work they have put in to develop and evaluate numerous variations of the delta sigH vaccine,” Dr. Kaushal said. “We are excited to move forward to the next stage of the process.”
Read more about the vaccine here:
TB vaccine candidate provides elite protection
Paper:
Garima Arora … Dhiraj K. Singh, Deepak Kaushal; Development and Preclinical Evaluation of Next-generation ΔsigH-based Live Candidate Vaccines. JCI Insight. Aug. 28, 2025 https://insight.jci.org/articles/view/195947