The results obtained in the treatment of 69 patients with trichomonal vaginitis and 46 patients with bacterial vaginitis with the immunotherapeutic agent Gynatren/SolcoTrichovac are presented. The number of lactobacillus colonies and variations in pH before and after treatment were studied in these two groups. The natural history of the vaginal ecosystem was reviewed and compared to the pattern of vaginal bacteria seen in nonspecific vaginitis. The hypothesis is advanced that the activity of Gynatren/SolcoTrichovac lies in an immunoreaction of type V, which involves the stimulation of the proliferation of lactobacilli that enhances the production of secretory IgA in the vaginal secretions.