The manufacture of conjugate vaccines is very complex. Carrier proteins and capsular polysaccharides are produced by fermentation processes, while capsular polysaccharide activation and conjugation to the carrier protein are chemically mediated. Process development requires a cross-discipline team of scientists with backgrounds in analytical chemistry, biochemistry, bioprocess, chemistry, engineering, statistics, and vaccines research. Throughout the development process, care must be taken to ensure that the physicochemical, biochemical, and immunogenic properties of the conjugate are consistently maintained across production scales. This talk will highlight some of the manufacturing and development challenges encountered with conjugate vaccines and potential mitigations.