Immunization, Vaccines and Biologicals

Tuberculosis vaccine development

Tuberculosis (TB) is the world’s leading infectious cause of death. It is estimated that about a third of the world’s population are infected with Mycobacterium tuberculosis (Mtb). Despite significant advances in reducing mortality in recent decades through improved diagnosis and drug treatment regimens, in 2015 an estimated 10.4 million people became ill with TB. In addition to enormous human suffering, TB causes substantial economic burden and is one of the major drivers of global inequity. Whilst neonatal BCG vaccination is partially efficacious at protecting infants and young children, particularly from the most severe consequences of TB disease, it is poorly protective against pulmonary disease in adolescents and adults, and therefore at reducing Mtb transmission. Reaching the WHO End TB Strategy targets of a 95% reduction in TB mortality and a 90% reduction in TB incidence, worldwide, by 2035, will require a new vaccine that is effective in adult individuals who have not yet been infected with Mtb, as well as in those with latent Mtb infection. Vaccines also offer the best chance to contain the accelerating spread of multi-drug resistant tuberculosis.

The TB vaccine candidate pipeline incorporates various vaccine platforms including whole cell vaccines, adjuvanted proteins, and vectored subunit vaccines. Candidate vaccines are being developed for prevention of TB disease in adolescents and adults, for early life immunization as BCG replacement, as BCG boosters, for vaccination of TB patients after treatment to prevent disease recurrence, or as immunotherapeutic adjuncts to drug therapy intended to reduce treatment duration. Currently, there is no coherently communicated consensus as to the preferred product characteristics (PPC) that would adequately support favorable policy recommendations for implementation where needed. The development of new TB vaccines has been identified as a priority for WHO Initiative for Vaccine Research, based on a high unmet medical need, technical feasibility assessment and potential value of WHO involvement, through PDVAC consultation. PDVAC called for the development of a document highlighting WHO preferred Product Characteristics (PPC) for new TB vaccines.

WHO has engaged into the development of new TB vaccines PPC(s). PPCs are official WHO guidance documents that describe WHO preferences for parameters of vaccines, in particular their indications, target groups, possible immunization strategies, and features of clinical data desired related to safety and efficacy, supportive of policy decision making. The primary target audience for the PPC is any entity intending to eventually seek WHO policy recommendations and prequalification for their products, required for procurement by UN agencies. Vaccine PPCs are built through a wide consensus building process and result from interactions with a variety of stakeholders. The draft WHO PPCs for new TB vaccines are now available for public review and comment.

Reviewers are kindly requested to relay comments via the provided Comment Review Form by 15 February 2018. Completed forms should be directed to: Dr. Johan Vekemans, Medical Officer, WHO IVB/IVR, E-mail: vekemansj@who.int

Please note that anonymous reviews will not be considered.

Draft WHO PPCs for public review and comment

Last updated: 26 January 2018