Immunization with the truncated adhesin moraxella catarrhalis immunoglobulin D-binding protein (MID764-913) is protective against M. catarrhalis in a mouse model of pulmonary clearance.

Most Moraxella catarrhalis isolates express the outer membrane protein MID. In addition to its specific affinity for immunoglobulin D, MID functions as an adhesin and binds to human epithelium. The adhesive part is localized within MID(764-913). Two mid-deficient M. catarrhalis isolates were constructed and examined in a mouse model of pulmonary clearance. M. catarrhalis devoid of MID was cleared more efficiently, compared with the wild-type counterparts. Furthermore, mice immunized with MID(764-913) cleared M. catarrhalis much more efficiently, compared with mice immunized with bovine serum albumin. MID(764-913) is suggested as a promising candidate in a future M. catarrhalis vaccine.