Acinetobacter baumannii has become an important cause of human infections, most notably in the hospital setting.
In addition, the global dissemination of multidrug resistant strains has complicated effective antibiotic therapy of infections
produced by this pathogen, necessitating the development of novel treatment and prevention strategies. Active
and passive immunization approaches have begun to be explored in experimental animal models as potential alternative
therapies for A. baumannii. In the present review, we discuss the advantages and disadvantages of each therapeutic strategy
with respect to A. baumannii infections, and summarize the recent studies that have explored these approaches. The
single antigen candidates that have been tested include, the outer membrane protein OmpA, the membrane transporter
Ata, the biofilm-associated protein Bap, the K1 capsular polysaccharide and the membrane associated polysaccharide
poly-N-acetyl-β -(1-6)-glucosamine. Strategies employing multicomponent antigens include inactivated whole cells, outer
membrane complexes and outer membrane vesicles. The strengths and limitations of each approach are discussed and the
challenges that remain to be addressed for successful A. baumannii vaccine development are highlighted.