Vaccines for the prevention of recurrent urinary tract infections:A systematic review

To systematically review the evidence regarding the efficacy of vaccines or immunostimulants in reducing the recurrence rate of urinary tract infections (UTIs).

MEDLINE, EMBASE, PubMed, Cochrane Library, WHO International Clinical Trials Registry Platform Search Portal, and conference abstracts were searched up to January2018 for English-titled citations.

Randomised placebo-controlled trials evaluating UTI recurrence rates in adult patients with recurrent UTIs treated with a vaccine were selected by two independent reviewers according to the population, interventions, comparators, and outcomes (PICO) criteria. Differences in recurrence rates in study populations for individual trials were calculated and pooled, and risk ratios using random effects models were calculated. Risk of bias was assessed using the Cochrane Collaboration's tool and heterogeneity was assessed using Chi-squared and I2 testing. The GRADE approach was used to evaluate the quality of evidence (QOE) and summarise findings.

599 records were identified, of which 10 studies were included. 1,537 patients were recruited and analysed, on whom data was presented. Three candidate vaccines were studied: Uro-Vaxom® (6), Urovac® (3), and ExPEC4V (1). At trial endpoint, the use of vaccines appeared to reduce UTI recurrence compared to placebo (RR 0.74; 95%CI 0.67-0.81; low QOE). Uro-Vaxom® showed greatest reduction in UTI recurrence rate; the maximal effect was seen at 3 months compared with 6 months after initial treatment (RR 0.67; 95%CI 0.57-0.78 and RR 0.78; 95%CI 0.69-0.88 respectively, low QOE). Urovac® may also reduce risk of UTI recurrence (RR 0.75 95%CI 0.63-0.89; low QOE). ExPEC4V does not appear to reduce UTI recurrence compared to placebo at study endpoint (RR0.82; 95%CI 0.62-1.10; low QOE). Substantial heterogeneity was observed across the included studies (Chi2 =54.58; p<0.00001, I2 =84%).

While there is evidence for the efficacy of vaccines in patients with recurrent UTIs, significant heterogeneity amongst these studies renders interpretation and recommendation for routine clinical use difficult at present. Further randomised trials using consistent definitions and end-points are needed to study the long-term efficacy and safety of vaccines for infection prevention in patients with recurrent UTIs. This article is protected by copyright. All rights reserved.

BJU international. 2018 Oct 30 [Epub ahead of print]

Nikoo Aziminia, Marios Hadjipavlou, Yiannis Philippou, Shivkumar S Pandian, Sachin Malde, Mohamed Y Hammadeh

Department of Urology, Queen Elizabeth Hospital, Woolwich, London, UK., Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK., Urology Centre, Guy's Hospital, London, UK.