Today marks an important landmark for the fight against tuberculosis (TB), a disease that kills more than 1.4 million people every year and that is proving increasingly resistant to treatment with antibiotics. We received clear results from the first large-scale clinical trial for a TB vaccine since the existing vaccine – known as Bacillus Calmette-Guerin (BCG) – was introduced more than 90 years ago.
The results, which were published today in The Lancet, showed that a vaccine candidate called MVA85A, while safe and well-tolerated by the nearly 3,000 South African children who received it, was no more effective in protecting infants from developing pulmonary TB than BCG alone.
While it is unfortunate that MVA85A failed to provide added protection against TB, the results provide us with a clear path forward to focus on other promising candidates. And the good news is that the research pipeline for a TB vaccine has never been stronger. There are more than a dozen TB vaccine candidates currently undergoing early phase clinical testing, and there are another 25 novel vaccines in pre-clinical research.
In addition to the scientific understanding that will be gained from the MVA85A trial, this trial brought together a talented group of scientists who are dedicated to accelerating TB vaccine research, and it built the research infrastructure – from laboratories and clinics to global collaborative partnerships –required to identify and evaluate promising candidates using the highest international standards.
Research to better understand the factors that enable most TB-infected individuals to control their infection and to develop improved animal models of infection and disease will also help guide vaccine design and evaluation.
The urgency for action is clear. In South Africa, where the trial was led by the South African Tuberculosis Vaccine Initiative, TB incidence has increased by 400 percent over the past 15 years. The global TB epidemic is becoming more complex and difficult to treat as drug-resistant strains of TB spread, devastating families and straining health systems from Durban to Delhi and from London to Beijing.
The need for improved preventive tools and improved drugs has never been more compelling. BCG is the most widely administered vaccine globally, and while it can prevent severe forms of TB in some children, its widespread use in infants has failed to control the global epidemic, which is fueled by adults and adolescents whose infection leads to pulmonary TB. Each year, nearly 9 million people become sick with TB globally, perpetuating cycles of infection.
This trial was a collaborative process, with funding provided by Aeras, a non-profit biotech with a social mission to develop TB vaccines; The Wellcome Trust; and the Oxford-Emergent Tuberculosis Consortium (OETC), a joint venture between the University of Oxford and Emergent BioSolutions. Aeras, which receives funding from the Bill & Melinda Gates Foundation, was the trial sponsor.