Table 1.

Identification of barriers to R&D for tuberculosis vaccines. The barriers to R&D for tuberculosis vaccines were grouped into four categories. In each category, key barriers were identified. The complete Global roadmap for research and development of tuberculosis vaccines is available at http://www.edctp.org/publication/global-roadmap-for-research-and-development-of-tuberculosis-vaccines/# (Courtesy of F. Cobelens).

Category	Specific barriers
Diversifying the pipeline	•Too narrow approach in regards to antigens, platforms, and delivery
Accelerating clinical development	•Lack of validated animal models that predict efficacy in humans •Lack of validated laboratory correlates for protection •Need for large-scale phase III trials with disease endpoint
Ensuring public health impact	•Lack of clear value proposition for countries to introduce a TB vaccine •Limited insight in how a TB vaccine for adults would be used & accepted •Poor insight in global and national demand and willingness to pay
Enabling conditions	•Limited and fragmented funding •Siloed science •Limited stakeholder engagement