Vaccine for Urinary Tract Infections Shows Early Promise

Urinary tract infections are painful and recur all too often with no apparent cause: Ask any woman who has missed days of work due to one, or had to find emergency treatment while on vacation.

University of Michigan scientists have made an important step toward what could become the first effective vaccine to prevent urinary tract infections, if the robust immunity achieved in mice can be reproduced in humans.

The research findings, which appear online Sept. 18 in PLoS Pathogens, could have broad effects, including reduced health care costs. Urinary tract infections (UTIs) affect 53 percent of all women and 14 percent of men at least once in their lives. They lead to lost work time and 6.8 million medical provider’s office visits, 1.3 million emergency room visits and 245,000 hospitalizations a year, with an annual cost of $2.4 billion in the United States.

U-M scientists screened thousands of bacterial proteins and identified three strong candidates to use in a vaccine to prime the body to fight Escherichia coli, the cause of most uncomplicated urinary tract infections. The vaccine prevented infection and produced key types of immunity when tested in mice.

“The results of our study are very encouraging. We would like to connect with interested clinicians and move on to a clinical trial,” says Harry L. T. Mobley, Ph.D., the study’s senior author and the Frederick G. Novy Professor and chair of the U-M Department of Microbiology and Immunology.

Other scientists have attempted to develop a vaccine for UTIs over the past two decades, but U-M’s potential vaccine has several strong points that may better its chances of success where other attempts have failed:
• It alerts the immune system to iron receptors on the surface of bacteria that perform a critical function allowing infection to spread.
• Administered in the nose, it induces an immune response in the body’s mucosa, a first line of defense against invading pathogens. The response, also produced in mucosal tissue in the urinary tract, should help the body fight infection where it starts.

Context

UTIs are of particular concern for people with repeated infections who may develop resistance to antibiotics commonly used as treatment. Factors that heighten the need for a vaccine, at least for people at greater-than-average risk, include increasing antibiotic resistance, allergic reactions and the unhealthy effects of antibiotics on beneficial microorganisms in the gut. Infections in the upper urinary tract are a particular concern in children, who may be left with permanent kidney damage.

Four out of five uncomplicated urinary tract infections, the type that sickens otherwise healthy people, are caused by certain strains of E.coli capable of infecting the urinary tract. Other types of E. coli not implicated in urinary tract infections include those that cause food poisoning outbreaks, as well as beneficial ones that live in the digestive tract.