α-Gal-Based Vaccines: Advances, Opportunities, and Perspectives

Humans and crown catarrhines evolved with the inability to synthesize the oligosaccharide galactose-alpha-1,3-galactose (alpha-Gal). In turn, they naturally produce high quantities of the glycan-specific antibodies that can be protective against infectious agents exhibiting the same carbohydrate modification on their surface coat. The protective immunity induced by alpha-Gal is ensured through an antibody-mediated adaptive and cell-mediated innate immune response. Therefore, the alpha-Gal antigen represents an attractive and feasible target for developing glycan-based vaccines against multiple diseases. In this review article we provide an insight into our current understanding of the mechanisms involved in the protective immunity to alpha-Gal and discuss the possibilities and challenges in developing a single-antigen pan-vaccine for prevention and control of parasitic diseases of medical and veterinary concern.