The One Health concept describes the relationship between human health, animal health and the environment, and recognizes how the interplay in this triad have led to the emergence and re-emergence of many diseases. Since 75% of known diseases are of animal origin and 60% of these affect humans, it is vital to combat animal pathogens to prevent zoonoses and sustain both animal and human health. It is for this reason that Afrigen serves both human- and veterinary vaccine developers. For veterinary vaccines, our core focus is on livestock zoonotic diseases and livestock diseases with high morbidity and mortality rates.
Inactivated- and live-attenuated vaccines are self-adjuvanted, whereas recombinant- and subunit vaccines require adjuvants to elicit potent immune responses due to the absence of pathogen-associated molecular patterns to which immune cells’ pathogen recognition receptors bind. Since the early 1920s, aluminium salts (i.e. aluminium oxyhydroxide and -phosphate) have been the adjuvant of choice for human vaccines due to its favourable safety profiles. Several next generation adjuvants are licensed (e.g. virosomes, MF59, R837/R848, AS04 and AS03) or in clinical trials (e.g. poly IC:LC, MDP, MPL, CpG ODN AS01, flagellin and AS02) for human vaccines. The use of next generation adjuvant formulations with TLR agonists are now more frequently used in human vaccine development. Next generation adjuvants in licensed human vaccines include MF59 (Fluad®), AS03 (Pandemrix®) and virosomes (Epaxal®, Inflexal® V) for influenza; AS04 (MPL+alum; CervarixTM) for human papilloma virus; and imidazoquinolines (e.g. imiquimod and resiguimod; AldaraTM) for topical applications. Next generation adjuvants in clinical trials for human vaccines include AS01 and AS02 (MPL+QS21) and saponin (QS21) for malaria, and GLA-SE (lipid A analogue) for TB. TLR agonists are formulated in emulsions and liposomes.