New Vaccines are Essential to End TB
Vaccines are one of the most successful and cost-effective public health interventions for reducing and even eliminating deadly infectious diseases. But the only licensed vaccine against TB, Bacille Calmette-Guérin (BCG), while moderately effective against TB in infants and young children, is unreliable in preventing TB in adolescents and adults, the population that bears the highest burden of disease.
Tackling Drug-Resistant TB
Antimicrobial resistance (AMR) is a growing public health threat, as bacteria evolve and treatments become less effective. In 2018 there were an estimated 375,000 new cases of multidrug-resistant TB (MDR-TB). An effective vaccine would contribute to efforts to address drug-resistant TB in several ways:
- New vaccines are likely to be equally effective against both drug-resistant and drug-sensitive TB, thus reducing incidence and transmission of MDR-TB.
- By preventing TB diseasees, vaccine would reduce the need for antibiotics.
- Therapeutic vaccines, used in combination with drugs, could reduce treatment duration and reduce the risk of recurrence.
New Vaccines are Achievable
Ninety percent of otherwise healthy individuals infected with TB do not progress to TB disease, indicating that the human body can already protect itself from TB in some cases. Scientists hope to replicate this innate resistance in a vaccine. And, the current vaccine, BCG, does offer partial protection, which is a positive indicator that it is possible to develop vaccines that offer better protection.
Recent positive results from two Phase 2b clinical trials, progress across the clinical pipeline, promising results of novel vaccine candidates in preclinical models, and enhanced understanding of the human response to Mtb infection support the feasibility of developing new, more effective vaccines.
Success Will Require Increased Investment
Vaccine development is a lengthy and expensive process. Substantial and sustained resources are needed to support and enhance the full continuum of research and development. It is estimated that at least $550 million will be needed per year to meet the objectives for TB vaccine development outlined in the Global Plan to End TB 2018-2022. This represents a fraction of the estimated $13 billion per year that the TB epidemic currently costs in prevention, diagnosis and treatment and would accelerate the development of this lifesaving intervention. But, despite the urgent need for new vaccines and continued progress in the field, TB vaccine research funding in 2018 was just over over US$109 million.