Formulations that stabilize and inhibit the precipitation of immunogenic compositions

A formulation that stabilizes a polysaccharide-protein conjugate, a formulation comprising (i) a buffered pH saline solution, in which the buffer has a pKa of 3.5 to 7.5, (ii) polysorbate 80 at a final concentration from 0.01% to 0.05% of polysorbate 80 by weight / volume of the formulation and (iii) one or more polysaccharide-protein conjugates in which the polysaccharide-protein conjugate comprises one or more pneumococcal polysaccharides .