Vaccines for recurrent urinary tract infections: evidence, challenges, and clinical potential

Recurrent urinary tract infections (rUTIs) impose a substantial clinical burden and frequently require repeated or prophylactic antimicrobial treatment. Increasing antimicrobial resistance and the limitations of long-term antibiotic exposure have stimulated interest in immunoprophylaxis as an antibiotic-sparing preventive strategy. This narrative review critically appraises current evidence for urinary tract infection (UTI) immunoprophylaxis, focusing on mechanisms, clinical efficacy, safety, evidence maturity and potential applicability to practice. A structured literature search of PubMed, Embase and Google Scholar was undertaken for English-language publications from 1 January 2000 to 31 December 2025. The evidence considered included systematic reviews and meta-analyses, randomised controlled trials, observational studies and, for emerging platforms without established human evidence, relevant preclinical studies. Evidence was synthesised narratively because of substantial heterogeneity in immunoprophylactic platforms, study populations, comparators, outcome definitions and follow-up. MV140 and OM-89 have the most developed human clinical evidence base among the approaches reviewed. A placebo-controlled randomised trial demonstrated reduced UTI recurrence with MV140, while secondary analysis identified reduced antibiotic exposure. OM-89 has been evaluated in multiple randomised trials and meta-analyses, although heterogeneity and attenuation of effects in more recent evidence limit certainty. Evidence for StroVac and Solco-UroVac is less consistent and is constrained by methodological limitations or older studies. ExPEC4V and FimCH have demonstrated immunogenicity and acceptable early-phase tolerability, but clinical efficacy in preventing rUTI has not been established. Multi-epitope vaccine approaches remain preclinical. Across platforms, heterogeneity in populations, endpoints, regimens and follow-up limits direct comparison. UTI immunoprophylaxis has potential as an antibiotic-sparing strategy for rUTI prevention, but the evidence is not sufficiently uniform to support assumptions of equivalent efficacy or broad routine implementation across platforms. Further, adequately powered randomised trials using standardised clinical and microbiological endpoints, systematic safety assessment, antibiotic-consumption outcomes and longer follow-up are required to define durability of benefit, appropriate patient selection and clinical and health-economic value.