This research is studying a new vaccine called ExPEC9V designed to prevent a serious illness called invasive extraintestinal pathogenic Escherichia coli disease (IED). IED is an infection caused by a type of bacteria, E. coli, that can spread from the urinary tract to other parts of the body. This study is for people 60 years and older who have had a urinary tract infection (UTI) in the past two years. The vaccine is compared to a placebo (a fake treatment) to see if it works better at preventing IED.

The study lasts up to 6 years and 9 months and includes several phases: starting with screening, randomization (participants are randomly chosen to receive either the vaccine or placebo), vaccination, and a follow-up phase lasting up to 4 years. Participants should be willing to provide medical information about their history of UTIs.

• Participants may receive a vaccine or a placebo.
• They need to visit the study site for various assessments.
• Participants may report any changes in health during the study.