Method and kit for making a polysaccharide-protein conjugate

A polysaccharide-protein conjugate prepared by a method comprising:

• a) oxidizing a polysaccharide with an oxidizing agent to form an oxidized polysaccharide and
• b) combining the oxidized polysaccharide with a protein in the presence of a macromolecular crowding agent,
• wherein the polysaccharide and protein form a Schiff base conjugate in the absence of a reducing agent.

A method for making a polysaccharide-protein conjugate microparticle comprising:

• a) oxidizing a polysaccharide with an oxidizing agent to form an oxidized polysaccharide, and
• b) combining the oxidized polysaccharide with a protein in the presence of a macromolecular crowding agent
• wherein the polysaccharide and protein form a Schiff base conjugate microparticle.

A polysaccharide-protein conjugate microparticle prepared by a method comprising:

• a) oxidizing a polysaccharide with an oxidizing agent, and
• b) combining the oxidized polysaccharide with a protein in the presence of a macromolecular crowding agent,
• wherein the polysaccharide and protein form a Schiff base conjugate.