Development of a serocorrelate of protection against invasive Group B Streptococcus disease (iGBS). 

Population: Maternal and Paediatric (babies up to 3 months of age). 

Disease group: GBS

Funder: Medical Research Council and Minervax. The other pathogens sub-study is funded by Pfizer. 

Sponsor: St George’s, University of London. 

Principal Investigators: Professor Paul Heath and Dr Asma Khalil 

Study Aims

Group B Streptococcus (GBS) in a major cause of sepsis and meningitis in newborns and can cause premature births and stillbirths as well as infections in pregnant women. It is normally carried in our intestines and only causes harm when it is passed from mother to baby around the time of birth or in the first months of life. It is estimated that GBS claims around 150,000 babies lives a year worldwide.  

iGBS3 is a research study of women’s natural immunity against GBS. We want to find out how much antibody a woman needs to pass to her baby to protect the baby from getting GBS disease. This will help in developing a vaccine.  

What does participating in the study involve? 

We will take a small sample of blood from a large number of women. Because this needs to be done just after delivering the baby, we will be using a verbal consent approach. Any women who does not want to give these samples can refuse at any time and no samples will be taken. Cord blood samples will be stored locally and then sent to St George’s, University of London.  

If a baby develops GBS disease in the first 3 months of age, the parent will be asked for written consent for us to retrieve the stored cord blood sample as well as an additional sample of blood from the baby in order to measure antibodies in it. These antibodies will be compared with the antibodies from GBS colonised women delivering infants who remained healthy.  

If you are a pregnant woman and would like more information about the study, please contact the study team on:  

If you have a baby and would like more information about the study, please contact the study team on:  

Or please visit the Vaccinology website for more information: 


A video from the Chief Investigator, Professor Paul Heath