Immunogenicity and protective efficacy of three Campylobacter jejuni flagellum-secreted proteins, FlaC, FspA1, and FspA2, were compared by use of a mouse model. Immunization with FspA1 resulted in 57.8% protection without adjuvant or 63.8% protection with adjuvant against homologous challenge with 81-176 (Baqar et al., 2008).