Nonencapsulated (nontypeable) Haemophilus influenzae (NTHi) is a Gram-negative coccobacillus colonizing upper respiratory tract of most healthy people and causing such diseases as otitis media, sinusitis, exacerbations of chronic obstructive pulmonary disease, and bronchitis. NTHi may cause systemic infection. As a result, over the past decade the bacterium has been the subject of intense research. However immune response to NTHi has not been well characterized. Data on research of immune response to NTHi are presented.