Matrix-M adjuvanted influenza vaccine

Matrix-M adjuvanted influenza vaccine is an investigational vaccine formulation that combines a standard influenza antigen (such as a split-virion or hemagglutinin protein) with the Matrix-M adjuvant. Matrix-M, originally developed by Isconova AB (later acquired by Novavax), is a saponin-based adjuvant composed of two distinct 40-nm nanoparticles containing purified saponin fractions (Fraction-A and Fraction-C) extracted from the *Quillaja saponaria* tree, combined with cholesterol and phospholipids. The adjuvant functions by activating innate immune cells, including dendritic cells, macrophages, and neutrophils, in the draining lymph nodes, which subsequently enhances both humoral (antibody) and cellular (Th1/Th2) immune responses. In Phase I clinical trials involving elderly volunteers, the Matrix-M adjuvanted seasonal influenza vaccine demonstrated superior immunogenicity, including improved hemagglutination inhibition (HI) titers and functional cellular immunity, compared to standard non-adjuvanted vaccines, while maintaining a manageable safety profile.

Other names

Matrix-M adjuvanted seasonal influenza vaccineMatrix-M adjuvanted VaxigripMatrix-M-Isconova AB-influenza