In short
Klebsiella pneumoniae (inactivated) is an investigational vaccine substance made from killed bacteria. It is being studied in a Phase 3 clinical trial for preventing or managing urinary tract infections (UTIs). The trial, registered as 2026-527508-25-00, involves 20 participants and is currently authorised to begin.
Key points
- Phase 3 trial evaluating an inactivated bacterial vaccine for urinary tract infections
- 20 participants planned for enrollment in the proof-of-concept study
- Trial status is Authorised in the EU Clinical Trials Information System
- Primary outcomes measure IgG antibodies in plasma and IgA antibodies in urine after vaccination
- The vaccine contains inactivated Klebsiella pneumoniae among 10 bacterial strains
- Study also tests laboratory methods for detecting functional antibodies in blood
What is Klebsiella pneumoniae (inactivated)?
Klebsiella pneumoniae is a type of bacteria that normally lives in the human gut and respiratory tract without causing harm. However, some strains can cause infections including pneumonia, urinary tract infections, wound infections, bloodstream infections, and meningitis. The inactivated form of this bacterium is used in an investigational vaccine product called StroVac, which contains killed bacteria from 10 specified strains including Klebsiella pneumoniae.
Some strains of Klebsiella pneumoniae are resistant to antibiotics, meaning standard treatments may not work effectively against them, which makes infections potentially difficult to treat. Research into Klebsiella pneumoniae has focused on antimicrobial resistance, virulence, and therapeutic strategies.
How does Klebsiella pneumoniae (inactivated) work?
The vaccine containing inactivated Klebsiella pneumoniae is designed to stimulate the immune system to produce antibodies against the bacteria. The clinical trial is specifically measuring whether vaccination leads to increased levels of immunoglobulin G (IgG) antibodies in blood plasma and immunoglobulin A (IgA) antibodies in urine against each of the 10 target bacterial strains. IgG antibodies are proteins in the blood that help the body recognise and fight infections, while IgA antibodies are found in mucous membranes and bodily fluids such as urine.
The study also aims to evaluate laboratory methods for detecting functional antibodies — antibodies that can actively help destroy bacteria. These methods include an opsonophagocytosis assay (OPA), which measures how well antibodies help immune cells engulf and destroy bacteria, an agglutination test, which detects whether antibodies cause bacteria to clump together, and a neutralisation test, which assesses whether antibodies can block bacterial activity.
Which conditions is it used or studied for?
- Urinary tract infection (UTI) — an infection affecting the bladder, urethra, or kidneys, which can cause painful urination, difficulty urinating, and other symptoms. The current trial is evaluating the vaccine in people with UTIs.
How is Klebsiella pneumoniae (inactivated) given?
The investigational product containing inactivated Klebsiella pneumoniae is formulated as StroVac injection suspension. According to the trial record, the product contains 501 mg of inactivated bacteria from specified Enterobacteriaceae strains and is administered by injection.
What do the clinical trials show?
One clinical trial is registered for this substance in the EU Clinical Trials Information System. The trial is a Phase 3 proof-of-concept study evaluating immunological assays using human blood and urine samples after vaccination with StroVac.
The trial is currently Authorised, meaning it has received regulatory approval to proceed. It plans to enroll 20 participants.
The primary outcomes measured are the increase of patient-specific IgG levels in plasma and IgA levels in urine against each of the 10 bacterial strains from baseline before vaccination to Visit 4 after vaccination.
What side effects are known?
No side effect information is available from the provided sources for this investigational vaccine.