The present invention relates to a novel process for purifying bacterial polysaccharide at room temperature. It is an efficient and scalable process for removing impurities from Neisseria meningitidis serogroup A (Men-A) polysaccharide which is capable of being used as such in a derivatized form or linked to other molecules, for the preparation of vaccines, more particularly conjugate vaccines for N. meningitidis infection.
