The treatment of UTIs has been highly affected by antibiotic resistance; thus, novel therapeutic approaches such as vaccines have gained popularity, especially, in the cases of recurrent UTIs. Our aim in this study was to systematically study the available vaccines and to perform a network meta-analysis.

A comprehensive search was done in PubMed, Embase, Scopus, and Cochrane Library for articles published until March 2022. Randomized placebo-controlled desmopressin trials assessing the UTI recurrence rates in adult patients with recurrent UTIs were included. The studies compared a vaccine type with a placebo. The risk of bias was assessed using the Cochrane risk of bias assessment tool by two reviewers. Data were extracted using an author-developed checklist. A systematic review was performed according to the Cochrane Systematic Reviews Guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist and network meta-analyses were performed.

The initial search resulted in 810 records of which 12 studies comprising 2030 patients were included. The included studies had moderate/low risks of bias; thus, no study was excluded. A comprehensive systematic review was done and network meta-analyses were performed for several outcomes including the reduction in the number of UTIs and the adverse events in each arm. Urovac (Solco Basel Ltd, Basel, Switzerland), Uro-Vaxom (OM Pharma, Myerlin, Switzerland), and ExPEC4V (GlycoVaxyn AG, Schlieren, Switzerland) were the included vaccines. Uro-Vaxom was the most effective in reducing the recurrence of UTI (RR: 0.62 [0.42, 0.90]) followed by Urovac (RR: 0.7 [0.41, 1.19]) and ExPEC4V (RR: 0.82 [0.34, 1.99]). The P-scores in the network ranking (using the random effect model) were 0.78 for Uro-Vaxom, 0.63 for Urovac, 0.43 for ExPEC4V and 0.14 for placebo. No statistically significant difference was reported when evaluating the adverse events of the vaccines when compared to placebo.

Uro-Vaxom was the most effective in reducing the recurrence of UTIs and the only vaccine with a statistically significant difference compared with placebo. The outcomes are promising, However, the study limitations due to the small sample sizes and short-term outcomes may have affected the results. Hence, more high-quality and long-term studies with uniform designs are needed because the lack of statistical significance does not mean a lack of clinical significance.

The results of this study show promising results for the use of vaccines to prevent recurrent UTIs. Uro-Vaxom seems to be the most effective vaccine for this use. However, due to the high heterogeneity and the limited number of studies, more high-quality randomized prospective trials are needed to help us understand the efficacy of these medications for the long-term well-being of the patients.