Mechanisms of the action of veterinary vaccine adjuvants

Adjuvants are used to induce increased immune responses of inactivated and subunit vaccines both in veterinary and human medicine. Vaccine producers must overcome serious challenges in order to develop safer and more efficient adjuvants without side effects. During the past decades the initial trial and error based approaches were gradually replaced by targeted developments. Most of the advances were due to the accumulation of detailed knowledge about the mechanisms of action of the adjuvants. In this review the authors describe the mechanisms of the most widely utilized adjuvants in the veterinary practice and that of the most promising ones under development.