Disclosed herein is a glycocojugate vaccine conferring protection against a Gram negative pathogen infection, a method of manufacturing the glycoconjugate vaccine, and use of the glycocojugate vaccine for treating bacterial infection. The glycocojugate vaccine of the present disclosure has the structure of formula (I), wherein, L is a maleimide-type linker, which is connected to the carrier protein via a maleimide bond formed therebetween; and n and m are respectively an integral or a non-integral number between 2 and 20.