killed NTHi H04-06 strain

killed NTHi H04-06 strain is an experimental vaccine candidate composed of an inactivated (killed) strain of non-typeable *Haemophilus influenzae* (NTHi), specifically the H04-06 strain. It is being investigated for its potential to induce strain-specific protective immunity against NTHi infections, which are a common cause of acute exacerbations in patients with chronic obstructive pulmonary disease (COPD). Studies in mouse models have shown that repeated intratracheal immunizations with this killed strain can lead to the production of cross-reactive immunoglobulins G and A in bronchoalveolar lavage fluids and enhance bacterial clearance of homologous NTHi strains in the lungs. The protective immunity is believed to involve outer membrane protein P2 and other surface antigens of NTHi.