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.
Rate of sustained TB infections
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.
New concepts in clinical trials
Jacqueline Shea 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."
BCG is the only licensed tuberculosis vaccine available globally. H4: IC31 is an investigative subunit vaccine candidate being developed jointly by Aeras and Sanofi Pasteur, the vaccines business of Sanofi (EURONEXT: SAN) (NYSE: SNY), and the Statens Serum Institut. The clinical trial was funded by Sanofi Pasteur, the United Kingdom's Department for International Development, The Bill & Melinda Gates Foundation and Aeras.
The clinical trial was conducted at the South African Tuberculosis Vaccine Initiative (SATVI) at the University of Cape Town and at the Emavundleni Research Centre (part of the Desmond Tutu HIV Centre). The study was approved by the Medicines Control Council of South Africa and the relevant local independent ethics committees.