Staphylococcus aureus, especially multidrug resistant strains, continu
es to be a leading cause of serious nosocomial infections. In spite of
the debate among investigators in the field, the discovery of serolog
ically distinct capsular polysaccharides on the surface of clinical is
olates has renewed the prospects for development of vaccines and passi
ve protective immunity against S. aureus infections. Capsular polysacc
haride conjugate vaccines have now been produced and proven to be safe
and immunogenic in both healthy and in a significant percentage of im
munocompromised patients. Antibodies generated in humans against these
vaccines have been shown to mediate type-specific opsonophagocytosis,
and to protect animals against lethal challenge with the appropriate
S. aureus isolate.