Meeting report: WHO consultation on Respiratory Syncytial Virus (RSV) vaccine development, Geneva, 25-26 April 2016.

Respiratory syncytial virus (RSV) is a leading viral cause of respiratory morbidity and mortality in infants and young children worldwide. Low and middle income countries (LMICs) account for approximately 99% of the global mortality estimates in this population, with up to 200,000 RSV deaths per year. The vaccine product development pipeline is diverse with the most advanced clinical candidate currently in phase III efficacy testing in pregnant women. In addition, a long-acting RSV-neutralizing monoclonal antibody (mAb) to be administered at birth to prevent serious RSV-related respiratory disease is in late stage clinical development, as are additional conventional mAb for use in high-risk infants. Thus, there is a realistic possibility that an effective new intervention to prevent RSV disease will be available in the next 5-10year horizon. In anticipation of this outcome, the Strategic Advisory Group of Experts for Immunization (SAGE), WHO's vaccine policy recommendation body, reviewed the status of RSV vaccine and monoclonal antibody development in April 2016. Although substantial progress towards licensure has broadened the research agenda to consider intervention impact and cost effectiveness, significant gaps remain in the data that will be needed to inform and support a policy recommendation for implementation. These aspects were the focus of WHO's second consultation on RSV vaccines and single dosage extended half-life mAb for prophylaxis.