Carbohydrate-based adjuvants

[Display omitted] •Carbohydrate-based adjuvants are safe, biocompatible and capable to stimulate strong and long-lasting humoral and cellular immune responses.•Lipid A derived compounds, as well as, chitosan, saponins and glucans continue to be commonly used as adjuvants, however, there is significant progress on the use of galactosylceramides, mannans, alginates and plant polysaccharides.•In nature a broad library of compounds is produced with vast diversity of potential biological activities, new natural sources of novel carbohydrate-based molecules should continue to be explored. Carbohydrate adjuvants are safe and biocompatible compounds usable as sustained delivery systems and stimulants of ongoing humoral and cellular immune responses, being especially suitable for the development of vaccines against intracellular pathogens where alum is useless. The development of new adjuvants is difficult and expensive, however, in the last two years, seven new carbohydrate-based adjuvants have been patented, also there are twelve ongoing clinical trials of vaccines that contain carbohydrate-based adjuvants, as well as numerous publications on their mechanism of action and safety. More research is necessary to improve the existent adjuvants and develop innovative ones.