antibody response in cholera‐endemic countries, vaginal priming with aberrant lactobacilli may be necessary for the generation of mucosal IgA-secreting plasma cells following parenteral vaccination. Effect on the vaginal ecology Protective lactobacilli inhibit the growth of other microorganisms by competing for adherence to epithelial cells and by producing antimicrobial compounds. These compounds include lactic acid, which lowers the vaginal pH, hydrogen peroxide and bacteriocins. Aberrant strains of Lactobacilli are incapable to effectively control the vaginal microbiota, leading to an overgrowth of a mixed flora of aerobic, anaerobic and microaerophilic bacterial species. Antibodies and cellular defense mechanisms directed against aberrant lactobacilli induced by vaccination have been shown to change the composition of the vaginal flora. Milovanović and his coworkers found a marked reduction in prevalence of Klebsiella and Proteus infestations in 36 trichomoniasis patients under therapy with SolcoTrichovac, while normal, metabolically active Lactobacillus species that could initially be found in only 11% of patients, were present in 72% after finishing treatment. Karkut observed a significant reduction in the incidence of Escherichia coli (55% to 23%), Group B Streptococci (37% to 10%), Enterococci (36% to 12%), Bacteroides (25% to 3%) and Gardnerella vaginalis (37% to 9%) in 94 patients treated for recurrent bacterial vaginitis eight weeks after initial injection. The incidence of aberrant lactobacilli fell from 17% to 3%, while that of normal lactobacilli rose from 31% to 72% during the course of the eight weeks. Harris reported a significant reduction of the number of microbial species (other than lactobacilli) found in post-treatment cultures from 77 patients. Litschgi found, that the incidence of mixed bacterial infections characterized by the presence of G. vaginalis, haemolytic Streptococci and Staphylococci was reduced by two-thirds four weeks after finishing therapy in 120 patients treated for bacterial colpitis. He observed a similar reduction of the less frequent Klebsiella, Proteus-dominant infections. A quantitative bacteriological analysis has been performed by Milovanović and coworkers in a group of 36 trichomoniasis patients. The study aimed at quantifying locally unusual and mostly pathogenic organisms, whereby anaerobes were excluded for methodological reasons. Bacterial counts of aerobes excluding lactobacilli reportedly dropped from 18,900 organisms per 0.1 ml vaginal secretion on the day of the first SolcoTrichovac injection to 5800 organisms 112 days thereafter. Goisis and his coworkers reported a mean count of lactobacilli of organisms per ml vaginal secretion before vaccination with SolcoTrichovac in 19 trichomoniasis patients. One month after the start of the treatment