Staphylococcal and Enterrococcal glycoconjugate vaccines are disclosed for use in preventing or treating bacterial infection in an immune-compromised individual. Such vaccines contain an immunocarrier and a conjugate of a polysaccharide or glycopeptide surface antigen from a clinically-significant bacterial strain. The vaccines can be used for active protection in immune-compromised individuals who are to be subjected to conditions that place them at immediate risk of developing a bacterial infection, as would be case in the context of a catheterization or a surgical procedure.