Pregnant women support Group B strep vaccine study to prevent baby deaths

Southampton researchers are inviting pregnant women to help study a new vaccine that would protect their baby from potentially life-threatening Group B streptococcus.

The clinical trial in Southampton and London is investigating the best time to offer the vaccine to guard against the common bacterial infection.

Protecting newborn babies

Group B streptococcus, also known as Group B strep, affects two to four in 10 women. It is usually harmless in adults but can be very dangerous to unborn and newborn babies.

It is responsible for nearly half of all life-threatening infections in newborns during the first three months of life. It also sometimes causes miscarriages, premature births and stillbirths.

It usually lives in the lower intestine (rectum) or vagina, and can infect babies during pregnancy and birth. It is not routinely tested for in pregnancy in the UK, but may be found during tests carried out for another reason, such as a urine test or vaginal swab.

The vaccine is being developed by Danish company MinervaX. The hope is that, by giving it to pregnant women, it will protect their baby during pregnancy and birth.

Dr Chrissie Jones, Southampton study lead, says: “A safe and effective Group B Strep vaccine would be a game-changer for newborn infants, both in the UK and globally. This is a significant infection in newborn babies, that can be life-threatening and can also cause long-term problems in those babies who recover from the infection.

“A vaccine against Group B Strep would be a massive step forwards in our ability to protect newborn infants from serious infection. We are inviting pregnant women from the Southampton area to help us test this vaccine.”

Developing the vaccine

In November, the World Health Organization reported the urgent need for a global vaccine against Group B strep. It linked the infection to over half a million preterm births annually, causing nearly 100,000 newborn deaths, at least 46,000 stillbirths, and significant long-term disability.

The MinervaX vaccine has already been given to non-pregnant women in a previous UK study, with no safety concerns.

It has been shown to induce a strong immune response – a sign it is effective – even in people with low levels of pre-existing immunity to the bacteria.

Pregnant women in South Africa, Uganda and Denmark have taken part in studies of this vaccine. All babies in the South African study have been born, with no serious side effects reported.

Taking part

Women who are pregnant without complications can take part in the study.

It is investigating the best time to offer the vaccine to pregnant women, to provide the most protection for their babies after birth.

The study is being held in the NIHR Southampton Clinical Research Facility, part of University Hospital Southampton NHS Foundation Trust, and St George's University Hospitals NHS Foundation Trust in London.

Participants will start the study at about 20 weeks of pregnancy and be followed through six months after delivery. There are 12 hospital visits in total including a screening visit. Volunteers can be reimbursed for travel costs.

For more information on the study, please contact