Lipophilic quaternary ammonium salt acts as a mucosal adjuvant when co-administered by the nasal route with vaccine antigens

Nasal administration of vaccines is an attractive approach which offers sev eral significant advantages over traditional intramuscular vaccine delivery . These advantages include easier administration and induction of immune re sponses in the mucosal secretions of the body. In this study we describe a new potent nasal adjuvant, dimethyldioctadecylammonium bromide (DDA), that induces both mucosal and systemic immune responses when co-administered wit h diphtheria toxoid (DT), tetanus toxoid (TT) and BBG2Na antigens. In parti cular, we show that the nasal delivery of recombinant fragment (BBG2Na) of the G protein of respiratory syncytial virus (RSV) mixed with DDA induces b oth local and systemic anti-RSV immune responses and protects against viral challenge. Furthermore, we provide evidence that the DDA + BBG2Na vaccine does not induce lung immunopathology upon subsequent RSV challenge. (C) 200 1 Elsevier Science Ltd. All rights reserved.