The present disclosure a cohort of sialic acid binding molecules which comprise one or more modified carbohydrate binding modules (CBMs). The modified CBMs reduce the risk of adverse events related to the host immune response and/or the production of anti-drug antibodies (ADAs). The modified CBMs can be used in therapy or as medicaments and find specific application as molecules for the modulation of an immune response and/or cell growth. The modified CBMs may also be used as adjuvants, for example mucosal adjuvants and in the treatment and/or prevention of cancer, sepsis and/or diseases caused or contributed to by a pathogen that binds cell surface sialic acid-containing receptors.