Immune system (stimulated by influenza virus antigens and MF59 adjuvant)

The immune system, when targeted by influenza virus antigens in combination with the MF59 adjuvant, undergoes a coordinated innate and adaptive response designed to provide prophylactic protection against influenza infection. MF59 is a squalene-based oil-in-water emulsion that acts as an immunopotentiator by creating a local immunocompetent environment at the injection site [1]. It triggers the secretion of chemokines like CCL2 and CXCL8, which recruit monocytes, macrophages, and dendritic cells to the site of administration [2]. These recruited cells efficiently internalize the influenza antigens, such as hemagglutinin (HA) and neuraminidase (NA), and transport them to the draining lymph nodes [1]. This process leads to enhanced differentiation of B-cells into antibody-secreting plasma cells and the expansion of antigen-specific T-cells [3]. This specific targeting strategy is particularly effective in older adults, where it helps overcome immunosenescence to produce a broader and more persistent immune response compared to non-adjuvanted vaccines [4].

Other names

Innate and adaptive immune systemMF59-adjuvanted influenza vaccine targetImmune system

MF59 induces a local immunostimulatory environment by recruiting and activating antigen-presenting cells (APCs) such as monocytes and dendritic cells to the injection site [1, 2]. These cells take up the co-administered influenza antigens (Hemagglutinin and Neuraminidase) and transport them to regional lymph nodes, where they trigger a robust adaptive immune response involving both B-cell antibody production and T-cell activation [1, 3].