In short
Enterococcus faecalis (inactivated) is a bacterial vaccine component used in StroVac, an injectable suspension studied for preventing recurrent urinary tract infections. One authorised Phase 3 trial is registered in the EU Clinical Trials Information System, planning to enrol 20 participants. The trial investigates whether vaccination with StroVac produces measurable antibody responses against ten bacterial strains, including Enterococcus faecalis, in blood and urine.
Key points
- Phase 3 proof-of-concept trial authorised in the EU Clinical Trials Information System.
- Studies StroVac, an injectable suspension containing inactivated Enterococcus faecalis and other specified enterobacteria.
- Planned enrolment of 20 participants.
- Focuses on urinary tract infection and immune response after vaccination.
- Measures IgG antibodies in plasma and IgA antibodies in urine against ten bacterial strains.
- Trial status is Authorised, meaning it has received regulatory approval to proceed.
What is Enterococcus faecalis (inactivated)?
Enterococcus faecalis is a bacterium that normally lives in the human intestine, where it can act as a commensal organism that produces vitamins, metabolises nutrients, and helps maintain intestinal pH. Inactivated Enterococcus faecalis is a form of this bacterium that has been killed or rendered unable to reproduce, so that it can be used as a vaccine component. In the registered trial, it is one of ten specified bacterial strains contained in StroVac, an injectable suspension. The substance is not described in the registry as an authorised medicine in its own right; it appears as an active component of a vaccine product under investigation.
How does Enterococcus faecalis (inactivated) work?
The registered trial is designed to find out whether vaccination with StroVac, which contains inactivated Enterococcus faecalis among other bacterial strains, leads to measurable immune responses. The trial measures patient-specific IgG antibodies in blood plasma and patient-specific IgA antibodies in urine against each of the ten target bacterial strains from before vaccination to after vaccination. The aim is to see whether the inactivated bacteria can stimulate the immune system to produce antibodies that recognise the bacterial strains contained in the vaccine. The trial also investigates whether functional antibodies can be detected using laboratory methods including an opsonophagocytosis assay, an agglutination test, and a neutralisation test with human serum.
Which conditions is Enterococcus faecalis (inactivated) used or studied for?
- Urinary tract infection — the registered trial studies StroVac, containing inactivated Enterococcus faecalis, in the context of urinary tract infection, focusing on immune responses after vaccination rather than on treating an active infection.
Beyond the registered trial, the supplementary sources describe Enterococcus faecalis in other clinical contexts. One source notes that Enterococcus faecalis is the most important bacterial species found in root canals of endodontically treated teeth with persistent infections. Another source reports that a metalloprotease produced by Enterococcus faecalis, called GelE, can compromise the epithelial barrier and contribute to intestinal inflammation in mice. These findings relate to the live bacterium and are not part of the registered vaccine trial.
How is Enterococcus faecalis (inactivated) given?
In the registered trial, inactivated Enterococcus faecalis is given as part of StroVac, described as an injectable suspension. The intervention is listed as a drug with a total amount of 501 mg of inactivated specified enterobacteria per application. The route of administration is by injection. The trial record does not provide further details on the number of doses or the schedule of vaccination.
What do the clinical trials show?
There is one registered trial for this substance in the EU Clinical Trials Information System. It is a Phase 3 proof-of-concept study with a planned enrolment of 20 participants, and its status is Authorised. The trial is interventional, meaning that participants receive the vaccine and then provide blood and urine samples for laboratory testing. The primary outcomes are the increase of patient-specific IgG levels in plasma and patient-specific IgA levels in urine against each of the ten target bacterial strains, measured from baseline before vaccination to Visit 4 after vaccination. The trial also evaluates whether laboratory methods can detect functional antibodies against the bacterial strains in blood after vaccination. The trial record does not state a completion date or report any results yet, because the study is authorised but not described as completed.
What side effects are known?
None of the supplementary sources provided reports side effects for inactivated Enterococcus faecalis or for StroVac. The registered trial record does not list side effects either. Therefore, no side effect information can be given on this page.