Group A Streptococcus is one of the bacteria that causes most illness and can also lead to death. There is a lack of both vaccines and appropriate treatments for serious conditions such as sepsis, where antibiotics may not be enough to save lives. Antibodies have been shown to be an effective treatment for other pathogens, but there are none for group A streptococcus, where one problem is the large number of bacterial variants. We have recently discovered a broadly protective monoclonal antibody against group A streptococcus, which we have raised from patients who have undergone infection. It is the first broadly protective antibody to be described. The fact that the antibodies are of human origin increases both safety and the chance that they can work as a treatment. We now want to develop some more broadly protective antibodies to create a clinical cocktail treatment. We have internationally leading methods available from ex vivo discovery, in vitro characterization and in vivo animal models. We see great clinical opportunities. Polyclonal antibody therapy has been tried, but the antibodies involved are not known, with unclear effects. Instead, we plan to put together well-characterized monoclonal antibodies as cocktails, where we also have the opportunity to improve properties through antibody design, something we have shown with our first antibody. As a combination therapy, it will be easy to administer with current antibiotic treatments for severe streptococcal infections.