A method of preventing or treating staphylococcal bacterial infection in an individual is disclosed. A vaccine based on a conjugate of PS1 polysaccharide antigen can be used for active protection in 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. Alternatively, antibodies raised in response to the antigen can be used to treat or to provide passive protection to individuals. The method can be used in a population of patients at risk for infection by various species of
