Antibody-secreting cells (ASC) and serum antibody response were measured in 15 adult volunteers immunized subcutaneously with group A and C meningococcal polysaccharide vaccine. The vaccine induced an IgA-dominated ASC response both to meningococcal group A (Men A) and group C (Men C) polysaccharides suggesting an activation of mucosa-committed B cells. Also the relative increase in serum IgA antibodies was higher than in IgC or IgM antibodies. The results support earlier studies showing that the T-cell independent polysaccharide antigens induce an IgA dominated antibody response and a mucosal response may be induced also by systemic administration.