The mechanisms of action of vaccines containing aluminum adjuvants: an in vitro vs in vivo paradigm
Excerpt: Aluminum compounds are the only adjuvants widely approved for use in human vaccines due to their safety record (BS), ease of preparation, stability and immunostimulatory (inflammatory) effects. Adjuvant development is undoubtedly a long process that must address regulatory, safety, and economic concerns, during clinical and preclinical development. Therefore, despite our incomplete understanding of the mode of action of aluminum based adjuvants, in the absence of suitable alternative adjuvants, alum is the sole candidate for use in human vaccines in the future. Considering the widespread use of alum, further comparative in vitro and in vivo should be undertaken to establish the mode of action due to the conflicting in vitro and in vivo data published. A clear causal association of alum in triggering immune responses via cellular death and or enhancing the quality, duration, and magnitude of T- and B- cell responses will make a significant contribution to the rational design of effective and safe vaccines and development of new adjuvants for future use.