ABSTRACTUrinary tract infections (UTIs) are common bacterial infections. Women are 8 to 30 times more likely to have this infection than men. The majority of women report at least 1 UTI in their lifetime. Within a year, about 25% or more of these patients will have a recurrence, and 22% will have recurrent UTIs (RUTIs). Continuous prophylaxis with antibiotics is commonly recommended as initial treatment for RUTIs. However, there is high risk for the development of multiresistance with their continuous use; in some regions of the world, more than 40% of the bacterial strains are already resistant to available antibiotics. Moreover, there is a high incidence of adverse reactions. To address these problems, preventive strategies such as vaccine use have been investigated that reinforce the natural mechanisms of pathogen defense. One such vaccine, Uromune, is an inactivated bacterial cell suspension composed of selected strains of Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, and Enterococcus faecalis.The aim of this multicenter retrospective observational study was to compare the clinical benefit of prophylactic use of Uromune with that of the currently accepted prophylactic treatment, sulfamethoxazole/trimethoprim (SMX/TMP) to prevent RUTIs. The authors reviewed the clinical history of 319 women who presented with RUTIs (defined as at least 2 episodes of UTI in the last 6 months or 3 in the last 12 months).Data collected before the initiation of the corresponding treatment and after 3, 9, and 15 months included number of UTIs and time of evolution of RUTIs before initiation of treatment. Patients in group A (n = 159) received prophylactic treatment with Uromune for a period of 3 months, and patients in group B (n = 160) received oral doses of SMX/TMP (200/40 mg/d) as prophylactic treatment for a period of 6 months.The data showed that patients in group A experienced a highly significant reduction in the mean number of infections in the first 3 months compared with patients in group B0.36 versus 1.60, P < 0.0001, respectively. There was also a significant reduction after 9 and 15 months (P < 0.0001). Significantly more patients in group A than in group B did not suffer any UTI at 3, 9, and 15 months101, 77, and 55 patients in group A versus 9, 4, and 0 patients in group B (P < 0.000).These data show that the use of this bacterial-based therapeutic vaccine could be an effective strategy to reduce frequency, duration, severity, and costs of RUTIs.