Selective Delipidation of Mycobacterium bovis BCG enhances its Vaccine Potential against TB
T2017-407 A novel method to increase vaccine effectiveness for TB
Tuberculosis (TB), caused by Mycobacterium tuberculosis (M.tb), is an infectious disease that kills one person every 21 seconds. TB is the current leading cause of death worldwide due to a single infectious organism, overtaking AIDS and malaria. TB treatment requires several months to years of chemotherapy and variable outcomes have led to the rise of drug-resistant strains that threaten eradication efforts.
Mycobacterium bovis BCG is the only live vaccine approved for TB prevention. However, while BCG is highly efficacious against extrapulmonary and disseminated forms of TB, its efficacy against pulmonary TB (PTB) is poor. BCG is currently administered intradermally, while the natural route of infection by M.tb is via the lung. This disparity is likely one of the underlying factors behind the poor efficacy of BCG against PTB. Excessive lung pathology caused by direct delivery of the current BCG vaccine into the lungs has prevented the use of this route of immunization.
Researchers at The Ohio State University have developed a technique using a delipidating agent to enhance the efficiency of the vaccine for TB. Treatment of the current vaccine, BCG, with the agent selectively extracts many of the inflammatory lipids from the BCG surface without affecting the viability. In pre-clinical studies, pulmonary vaccination with this novel delipidated BCG (dBCG) attenuated inflammatory responses and prevented immunopathology of the lung (the hallmark of TB), removing the major concern regarding the use of this route of administration. These and further results are evidence that selective delipidation of the current BCG offers a novel, safe, and effective pulmonary vaccine against TB that can easily be expedited into clinical trials.
- Tuberculosis Vaccination
- dBCG pulmonary vaccination was significantly superior to the current BCG at reducing bacterial burden in the lung and peripheral organs of M.tb infected animals and reduced immunopathology of the lung caused by M.tb.
- dBCG does not induce pathology in the lung compared to conventional BCG
- Because the current BCG is already approved worldwide, it is probable that approval and implementation of the modified dBCG can proceed on a fast track
- The delipidation method is inexpensive, fast and easily accomplished