New research from the University of Sheffield and the MRC Unit The Gambia at the London School of Hygiene and Tropical Medicine has, for the first time, identified the specific antibodies that may protect children from Strep A - a bacterial infection that kills around 500,000 people year globally
The study tracked children in The Gambia, and discovered that while maternal protection fades, young children rapidly develop immune responses to parts of the bacteria, highlighting crucial insights for vaccine development
These findings, published in Nature Medicine, provide vital insights for creating a safe and effective Strep A vaccine, which could save hundreds of thousands of lives, particularly in low and middle-income countries
Scientists have discovered how some children develop natural immunity to a bacterial infection, a vital breakthrough which could help develop vaccines to save up to half a million lives globally each year.
The new research from the University of Sheffield marks a significant step towards preventing Strep A, a common bacterial infection which often causes a mild sore throat or skin infections - but can sometimes be life-threatening.
In low and middle-income countries hundreds of thousands of people die each year after contracting the infection. This increased risk in countries such as The Gambia is often linked to heart damage resulting from repeated infections.
While deaths from Strep A are relatively uncommon in more affluent nations by comparison, it can still pose a serious risk. For example, a deadly Strep A outbreak in the UK and Europe in late 2022 resulted in hundreds of deaths, including many children.
By tracking how children in The Gambia develop natural immunity to Strep A, the research team was able to identify the specific antibodies that are linked to protection from the potentially fatal infection.
Working in partnership with the Medical Research Council (MRC) Unit The Gambia at London School of Hygiene and Tropical Medicine, the Sheffield research team has published its findings today in Nature Medicine.
Dr Alex Keeley, a Wellcome Clinical PhD Fellow in Global Health at the MRC Unit the Gambia and the University of Sheffield's Florey Institute of Infection, led the research.
"Our findings represent a significant step towards a safe and effective vaccine that could save around half a million lives here in the UK and around the world," said Alex.
"Historically we have not had the understanding of how people develop natural immunity to Strep A, making the development of a potentially life-saving vaccine incredibly challenging.
"Now, for the first time in humans, we've been able to observe how antibodies that would be made following vaccination may be preventing infections and show how these antibodies may be working against Strep A."
The study looked at how antibodies - our natural defenses against infection - develop in people in The Gambia from birth and throughout their lives. It found that while infants are born with some maternal protection against Strep A, that quickly fades away. Young children rapidly develop antibody responses to various parts of the bacteria after exposure to Strep A. Identifying this key window for developing immunity is a critical discovery for future vaccine strategies.
"It has long been recognised that a lack of understanding of natural immunity to Strep A is a significant barrier to developing a vaccine," Alex continued.
"Now we know how crucial the first few years of life are in developing immunity to Strep A, we can gain a much deeper understanding of how this immunity is developed.
"We hope this will lead to vaccine trials in different parts of the world to ultimately prove that vaccines can provide safe and effective protection against Strep A."
Fatouamta Camara, a scientist from The Gambia who played a key role in delivering the study, explains the potential impacts of the team's work: "In The Gambia, Strep A carries a devastating burden on children and adults in their prime years.
"Beyond causing illness, its impact ripples through families and communities, perpetuating cycles of poverty and reducing quality of life. A vaccine offers hope as a powerful tool to prevent these infections, protect our communities, and improve health outcomes, enabling children and young people to thrive."
The research project initially began as a collaboration between the Florey Institute of Infection and leading vaccine manufacturer, the GSK Vaccine Institute for Global Health (GVGH).
This gave Dr Keeley the opportunity to train in immunoassays - laboratory tests that measure antibodies and other immune responses in a sample. He was able to then train a small team of scientists, and conducted the study at the MRC Unit The Gambia. This partnership led to the findings reported in the newly published Nature Medicine study.
Professor Thushan de Silva, Co-Director of the Florey Institute of Infection in Sheffield and a Principal Investigator at the MRC Unit The Gambia, supervised the research. He said: "This study reflects the value of working across institutions to deliver high-quality and impactful research in global health. It also highlights the importance of Wellcome Trust support for Clinical PhD programmes, which enable the next generation of scientists to train and develop in internationally collaborative environments."
