Vaginal Mucosal Immunization for Recurrent Urinary Tract Infection: Extended Phase II Clinical Trial

Many women remain susceptible to ascending urinary tract infections (UTIs) despite the absence of a demonstrable anatomic abnormality [1]. Repeated treatment with antibiotics is often necessary for these women but may lead to adverse reactions and infection with antibiotic-resistant organisms [2]. On the basis of concepts of mucosal immunity in the genitourinary tract [3–5], we have been working to develop an effective mucosally applied vaginal immunogen to help prevent ascending UTIs. After a trial in nonhuman primates, we carried out and reported two previous clinical trials in susceptible women [6–8]. We are now reporting on a clinical trial to extend the time period of protection through use of the same multivalent vaginal immunogen and through immunogen boosts given at 4-week intervals SolcoUrovac (Solco Basel) is a whole-cell vaccine containing heat-killed bacteria from 10 human uropathogenic strains, including 6 Escherichia coli strains and 1 strain each of Proteus mirabilis, Proteus morganii, Enterococcus faecalis and Klebsiella pneumoniae [9]. The virulence characteristics of the included bacteria, the vaccine preparation, and the antigenicity of the vaccine have been described [9, 10]. For this extended phase II clinical trial, one ampule of vaccine (2×109 killed organisms/ampule) was incorporated into a vaginal suppository, and patients were randomized as described elsewhere [8]. There were 3 randomized treatment groups: Group 1 received vaccine suppositories at weeks 0, 1, 2, 6, 10, and 14; group 2 also received vaccine suppositories at weeks 0, 1, and 2 but at weeks 6, 10, and 14, they received placebo suppositories; and group 3 received six placebo suppositories at the same time points. All patients were followed through 24 weeks