STREPTOCOCCUS AGALACTIAE, SEROTYPE III, CAPSULAR POLYSACCHARIDE, CONJUGATED TO CRM197

Table of contents

• What is Streptococcus Agalactiae?
• How does Streptococcus Agalactiae work?
• Which conditions is Streptococcus Agalactiae used or studied for?
• How is Streptococcus Agalactiae given?
• What do the clinical trials show?
• What side effects are known?

What is streptococcus agalactiae?

Streptococcus Agalactiae, also known as Group B Streptococcus 6-Valent Polysaccharide Conjugate Vaccine (GBS6), is an investigational vaccine. Its full name is STREPTOCOCCUS AGALACTIAE, SEROTYPE III, CAPSULAR POLYSACCHARIDE, CONJUGATED TO CRM197. The vaccine is not yet authorised as a medicine; it is being studied in clinical trials.^[1]

The vaccine is designed to protect against group B streptococcus (GBS) disease, an infection caused by the bacterium Streptococcus agalactiae. GBS can cause serious illness in newborn babies, including infections of the blood, lungs, and membranes around the brain.

How does streptococcus agalactiae work?

The vaccine is a polysaccharide conjugate vaccine. It contains capsular polysaccharides from six GBS serotypes (Ia, Ib, II, III, IV, and V) that are chemically linked, or conjugated, to a carrier protein called CRM197. This conjugation helps the immune system recognise the polysaccharides and produce antibodies against them.^[1]

When given to a pregnant woman, the vaccine is intended to stimulate her immune system to produce antibodies against GBS. These antibodies can then pass through the placenta to the developing baby, providing the infant with protection against GBS disease in the first months of life.

Which conditions is streptococcus agalactiae used or studied for?

The vaccine is being studied for one main condition:

• Group B streptococcus (GBS) disease — an infection caused by the bacterium Streptococcus agalactiae that can cause serious illness in newborns, including early-onset disease (EOD) in the first week of life and late-onset disease (LOD) up to three months of age.^[1]

How is streptococcus agalactiae given?

In the clinical trial, the vaccine is given as an intramuscular injection. The trial record lists a dose of 00 Aµg/ml microgram(s)/millilitre, which means the exact dose was not reported in the register.^[1] The vaccine is administered to healthy pregnant women during pregnancy, with the aim of protecting their infants after birth.

What do the clinical trials show?

One Phase 3 trial (NCT07160244) is authorised to study the vaccine. The trial plans to enrol 12,000 participants, including healthy pregnant women and their infants.^[1]

The trial is measuring several outcomes. These include prespecified local reactions such as redness, swelling, and pain at the injection site, and prespecified systemic events such as fever, nausea, vomiting, diarrhoea, headache, fatigue, muscle pain, and joint pain. It also measures adverse events, serious adverse events, medically attended adverse events, and adverse events of special interest.^[1]

A key outcome is the level of GBS serotype-specific anti-CPS IgG antibodies measured at birth in infant participants. These antibody levels are used to estimate the predicted vaccine efficacy against invasive GBS early-onset disease and late-onset disease caused by the six vaccine serotypes.^[1]

The trial status is Authorised, meaning the trial has received approval to begin but has not yet started recruiting participants.

What side effects are known?

The trial is designed to assess the safety and tolerability of the vaccine in maternal participants and to assess the safety of maternal immunisation in infants. The outcomes being measured include local reactions at the injection site, systemic events, adverse events, serious adverse events, medically attended adverse events, and adverse events of special interest.^[1] No side effect data from completed studies are available in the provided sources.