Acute rheumatic fever (ARF) and its serious complication rheumatic heart disease (RHD) are preventable diseases triggered by the bacterium S. pyogenes, more commonly known as a group A strep. NZ has unacceptably high rates of ARF in Māori and Pacific children, which cause unnecessary suffering and death. Despite the knowledge that ARF is a disease with a known triggering agent, there are no vaccines available for group A strep infections. NZ has a unique opportunity for rheumatic fever research, having a large stock of group A strep isolates, collected from children with pharyngitis and skin infections. This combined with our high rates of ARF, provides researchers the ability to intercept isolates prior to a person developing ARF. Findings from this pilot study will provide critical knowledge about the pathophysiology of ARF as well as guiding vaccine development efforts.