A Vaccine for Strep A May Finally Be in Reach 

As invasive Strep A and scarlet fever cases surged across Europe, North America, Australia, and East Asia in the winter of 2022–2023, the WHO issued an alert. A few thousand deaths later, the outbreak was over. But almost nobody mentioned that Strep A—the bacterium behind strep throat and impetigo—kills more than 630,000 people a year, mostly young people in low- and middle-income countries.   

I have spent my career working on vaccines. Until I joined ​Coefficient Giving​, I had never heard Strep A mentioned as a global health priority, nor had my colleagues. The more I looked, the harder it was to understand why.  

Most Strep A deaths are linked to rheumatic heart disease (RHD), where the body’s immune response to repeated infections misfires and damages heart valves. A century ago, RHD was a leading cause of childhood deaths across North America, Britain,​ and Europe. W​hat ended it wasn’t a vaccine. It was ​​​better housing, sanitation, healthcare, and antibiotics​​. Children in wealthy countries still get Strep A, but they just don’t get it often enough or for long enough for the immune response to misfire. Break the chain of repeated infections, and RHD largely disappears.   

But it hasn’t vanished completely. Globally, around 55 million people live with RHD today.  

And yet, crude ​​​​whole-bacterium vaccines (made from the entire pathogen rather than selected components that modern vaccines rely on) tested in the early 20th century have already shown that Strep A vaccines could work. With Strep A, it’s not that we have tried to develop modern Strep A vaccines and failed; it’s that we have mostly failed to try.  

Strep A vaccine R&D is chronically underfunded, even compared to diseases with similar mortality like malaria and HIV—due largely to the complexity of the pathogen, a disease burden concentrated in LMICs, and lingering caution from historical safety concerns about earlier vaccine candidates. Across ​​​​200+ potential philanthropic focus areas Coefficient Giving has assessed over the last decade, rarely have we seen anything this neglected relative to the scale of the burden.  

That’s why Coefficient Giving has launched a ​fund to accelerate Strep A vaccine development.​The case for acting now is unusually strong. Multiple candidates are approaching clinical trials, and a Strep A challenge model has opened a faster path to efficacy signals. Researchers in Uganda have also shown that echocardiography detects early, asymptomatic RHD in around 2% of children, raising the possibility of a surrogate trial endpoint––​​​a measurable marker that substitutes for the long-term outcome and doesn’t require decades of follow-up, much like the ​​​​surrogates used for HPV vaccine development.​ 

But getting a vaccine to work is only half the battle. It took six years to shepherd RTS,S, the first malaria vaccine, from Phase 3 results to a WHO recommendation—and its impact was limited by cost and supply until R21, the cheaper, more scalable malaria vaccine I worked on, followed two years later. ​​​ ​​​​​  

We’ve built ​the Strep A ​​ ​fund to ​try ​to​ ​prevent those delays: supporting multiple candidates in parallel, engaging regulators early on trial endpoints, and investing now in the evidence and policy work needed for ​approval and ​deployment.    

By 2031, we want more vaccines in human trials and at least one ready for Phase 3 with a clear path to licensure. None of this is guaranteed. Candidates may fail, and regulators may want data we cannot easily generate. But based on ​​the ​​evidence available, Strep A looks more tractable than many of the unsolved infectious disease problems. A small group of researchers and funders have made amazing progress with limited funding. They have put us in a position where a serious push could finish the job.  

​​In high-burden settings, a child doesn’t get the occasional Strep A infection. They get repeated throat and skin infections in homes where transmission never really stops, increasing the risk of lasting heart damage​. ​     ​​​ ​​​​​  

Economic development could one day end this disease. A vaccine could do it now.  

Katharine Collins, PhD,​ ​​​​MBiol, ​a senior program officer in Coefficient Giving's Science and Global Health R&D Fund, manages a portfolio of grants covering malaria, Strep A, vaccine and adjuvant development, and vaccine delivery. Earlier, as a malaria researcher at the University of Oxford in the UK, QIMR in Australia, and RUMC in the Netherlands, she worked across the translational research pipeline—from early vaccine design and development to clinical evaluation in malaria-endemic settings, with various projects in Burkina Faso, Kenya, The Gambia, and Mali—and co-invented the R21/Matrix-M malaria vaccine now being rolled out in Africa.   

Join the 50,000+ subscribers in 170+ countries who rely on Global Health NOW summaries and exclusive articles for the latest public health news. Sign up for our free weekday newsletter, and please share the link with friends and colleagues.