Bradford scientists are developing a lifesaving vaccine for newborns to guard against a bug which kills 100 babies a year.

In 2003 3,500 babies in West Yorkshire were colonised with Group B Streptococcus (GBS), the most common bacterium affecting babies at birth. Of those, 20 developed a severe infection and three died.

The bug can cause pneumonia, blood infections and meningitis and it can kill babies within 24 hours of birth or lead to lengthy stays in hospital.

Babies catch the bacteria from mothers at the time of delivery and many pregnant women are unaware they are carrying GBS as there are usually no symptoms.

Now a team of microbiologists from the University of Bradford say they are a step closer to developing a vaccine which will protect a newborn from being infected by the bacteria from its mother. It would be given to mums-to-be found to be carrying the bug.

The research is being carried out by Beverley Bray, 25, a PhD student from the Department of Biomedical Sciences, under the supervision of research leader Dr Dean Harrington. They are focusing their work on structures on the bacterium's surface - lipoproteins - which they think may be important in several processes, including attaching GBS on to the baby's own cells.

Mrs Bray said: "At the moment we don't know why GBS is so virulent, so we need to understand how it sticks itself to a baby's cell surfaces to give us a chance of creating a vaccine. If, ultimately, we can develop an effective vaccine from lipoproteins, we could prevent colonised mothers transmitting the bacteria to newborns.

"This will remove the need to treat large numbers of mothers and babies with antibiotics."

At the moment if a woman is found to be colonised with GBS, antibiotics are given intravenously when she goes into labour. This relies on women being screened for the bacterium, which is not offered to mums-to-be on the NHS, although private testing is available.

Jane Plumb, chairman and co-founder of the charity Group B Strep Support, said: "A safe and reliable vaccine against GBS infection in babies would be brilliant. It could protect more babies from these infections than any methods we currently have. It could also overcome some of the main problems with screening women for GBS carriage and treating them in labour. A vaccine could mean many mothers and their babies wouldn't need antibiotics, which is good news."

Mrs Bray presented interim results of her research at a recent meeting of the Society of General Microbiologists at Keele University in Staffordshire.

Initial findings of the research are expected to be published next year.