Safety assessment of adjuvanted vaccines: Methodological considerations

Adjuvants mainly interact with the innate immune response and are used to enhance the quantity and quality of the downstream adaptive immune response to vaccine antigens. Establishing the safety of a new adjuvant-antigen combination is achieved through rigorous evaluation that begins in the laboratory, and that continues throughout the vaccine life-cycle. The strategy for the evaluation of safety pre-licensure is guided by the disease profile, vaccine indication, and target population, and it is also influenced by available regulatory guidelines. In order to allow meaningful interpretation of clinical data, clinical program methodology should be optimized and standardized, making best use of all available data sources. Post-licensure safety activities are directed by field experience accumulated pre- and post-licensure clinical trial data and spontaneous adverse event reports. Continued evolution of safety evaluation processes that keep pace with advances in vaccine technology and updated communication of the benefit-risk profile is necessary to maintain public confidence in vaccines.