Trial offers hope for new revaccination strategies with Bacille Calmette-Guerin (BCG) against Tuberculosis, the world’s leading infectious disease killer
Aeras, a nonprofit organization dedicated to developing vaccines against tuberculosis (TB), announced the publication of the full results from a Phase 2, randomized, controlled clinical trial of two TB vaccines– the currently available BCG vaccine and an investigational vaccine, H4:IC31–in the New England Journal of Medicine (NEJM).
This proof-of-concept study showed that vaccination can reduce the rate of sustained TB infections in a high-transmission setting, such as in uninfected, healthy adolescents in the Western Cape of South Africa where the study was conducted. In the trial, revaccination with BCG significantly reduced sustained TB infections in adolescents with a 45.4% vaccine efficacy. H4:IC31 also reduced sustained infections, although not at statistically significant levels, showing 30.5% vaccine efficacy. However, the trend observed for H4:IC31 is the first time a subunit vaccine has shown any signal that it may be able to protect against TB infection or disease in humans. In the trial, TB infections were measured by a blood test (QuantiFERON-TB Gold In-Tube (QFT)) converting from negative to positive, and sustained infections were defined by a QFT test that remained positive for at least six months.
Jacqueline Shea, PhD, Chief Executive Officer at Aeras, said: “With this study, we showed that vaccines against TB infection can work. The results highlight the importance of investing in new approaches to fighting the leading infectious disease killer and to evaluating new concepts in clinical trials. Further, the collaborative effort established between industry leaders, nonprofits and clinical sites during this trial showed how powerful combining such forces can be for developing new interventions against a global health threat. The BCG results are important findings with significant public health implications that could lead to saving millions of lives. Likewise, the novel prevention-of-infection trial design can be used to inform clinical development of new vaccine candidates before entry into large-scale prevention-of-disease efficacy trials. We are very grateful to the trial participants and our partners and funders who enabled the conduct of this trial.”
Initial results from the study were presented at the 5th Global Forum in New Delhi, India in February 2018.