Group A Streptococcus (GAS) infection is a major cause of death and disability globally with a disproportionately high burden in settings of disadvantage worldwide. Acute infections due to GAS range from very common superficial skin infections (\>150 million prevalent cases) and pharyngitis (over 600 million incident cases) to life-threatening invasive disease (\>600,000 incident cases) such as necrotising fasciitis. Post-infectious GAS sequelae of GAS include acute rheumatic fever (ARF, \~500,000 incident cases) leading to rheumatic heart disease (RHD, \~34 million prevalent cases), and acute glomerulonephritis. The health services impact of GAS disease in all its forms is immense and strikes at every level from primary to intensive care. Controlled human infection models (CHIMs) have a long history of critical contributions to vaccine development. Data from CHIMs meeting modern scientific, regulatory, and ethical standards, are aiding efforts to control over 25 major human pathogens, including bacteria (e.g. pneumococcus, cholera), viruses (e.g. respiratory syncytial virus, influenza), and parasites (e.g. malaria, schistosomiasis). A reliable and safe controlled human infection model of GAS pharyngitis will be an important part of the global vaccine development effort. To build the model, the investigators are undertaking a dose-ranging study using an observational, dose-escalation, inpatient trial to determine the dose of GAS administered by direct oropharyngeal inoculation (bacteria 'painted' onto throat) required to reliably produce a pharyngitis attack rate of ≥ 60% in carefully screened healthy adult volunteers.
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Proportion of participants at each GAS M75 dose level meeting the study pharyngitis endpoint
Timeframe: Up to 6 days after challenge dose administered.