Nanoscale alum-based adjuvants: Current status and future prospects

The effectiveness of vaccines can be greatly enhanced by using nanomaterials in formulation strategies. One example of this strategy is the modification of vaccine adjuvants into a nanoscale level. Due to a higher surface area to volume ratio, nanoscale adjuvants could facilitate higher antigen absorption and stimulate antigen-presenting cells (APCs) more effectively, resulting in increased adjuvanticity. This review highlights the current status and future prospects of nanoscale aluminum salts (alum), the most used adjuvants in vaccine formulation, particularly focusing on the preparation methods and the subsequent effects on enhancing immune responses.