Prolactin and NK cells in maternal malaria.

The decline to low or undetectable SBA and IgG antibody levels within a year after completion of primary MACC immunization (table 1) indicates that long-term protection can be achieved only if children are primed for memory responses and can rapidly produce specific IgG of relatively high avidity on encounter with the appropriate antigen. Further studies to investigate the kinetics of the serum and mucosal antibody responses after nasal challenge with meningococcal serogroup A antigen are warranted. In addition, it is unclear why immunologic memory is not induced in children immunized with the same MACC vaccine in The Gambia, as determined by the magnitude of the booster response to a polysaccharide challenge [3]. Investigation of avidity maturation in this population may be informative.