Klebsiella pneumoniae (KP) is a critical gram-negative opportunistic pathogen, causing not only nosocomial infections that can be antibiotic resistant but also leading to pyogenic liver abscess (PLA) disease. Armed with knowledge of the chemical structures of K. pneumoniae K1 and K2 surface capsular polysaccharides (CPSs) and their CPS depolymerases from bacteriophages, we developed potential glycoconjugate vaccines against this organism. This was done by using CPS polymerases present in tail spike proteins (TSPs) of specific KP bacteriophages to cleave the CPS and then chemically conjugating the fragment oligosaccharides to carrier proteins.