ObjectiveTo review the progress that has been made in developing effective vaccines against the major bacterial pathogens responsible for acute otitis media.Data SourceReview of the literature with the aid of the MEDLINE database using the search termsotitis mediaandotitis media and vaccine.Data ExtractionData were collected from clinical trials and laboratory studies.FindingsThe heptavalent pneumococcal conjugated vaccine, Prevnar, reduced the incidence of acute otitis media from all causes by 7% in one study and by 6% in another study. For culture-positive pneumococcal otitis media, the point estimate of efficacy was 66.7% in one study, and the reduction in incidence was 34% in another study. A Phase I clinical trial has been completed successfully for a conjugated vaccine against nontypeableHaemophilus influenzae(NTHi), which has high immunogenicity for mice and rabbits, induces complement-mediated bactericidal activity against NTHi in rabbits, and is protective against NTHi otitis media in chinchillas. A conjugated vaccine againstMoraxella catarrhaliselicits strong immune responses in mice and rabbits and induces complement-mediated bactericidal activity in rabbits.ConclusionThe prevention of otitis media is likely to require multivalent pneumococcal, NTHi, andM. catarrhalisvaccines, and these vaccines likely can be developed within a decade.