The role of specific antibody in neonatal bacterial infections: an overview

Neonatal infections caused by GBS are commonly associated with a deficiency of IgG antibody to the type-specific polysaccharide of the infecting organism. The prevalence and importance of human antibody to specific surface proteins, which are very common in clinical GBS strains, are unknown. Type-specific antibody is sufficiently prevalent that immunoglobulin preparations for both intramuscular and intravenous use contain animal-protective, opsonic antibody for many GBS strains. The availability of polysaccharide vaccines suggest that even more potent, "hyperimmune" preparations can be prepared from immunized volunteers. The importance of selective antibody deficiency in K1 E. coli infections of newborns is less clear. Protective, opsonic antibody is more difficult to demonstrate in human serum, but activity has been shown in some IGIV preparations. The specificity of the active antibody and the feasibility of producing hyperimmune IGIV against K1 E. coli are unknown at this time.