A Strep Throat Controlled Human Infection Trial in Healthy Adults

This aim of this study is to further develop a new way to study the bacteria that causes pharyngitis (strep throat). The scientific name for this bacterium is Streptococcus pyogenes and it is commonly known as Strep A. Strep A is a common type of bacteria that can cause various infections. These range from skin infections and strep throat to more serious conditions like rheumatic heart disease. In recent years there has been an increase in severe Strep A infections in most countries. Many of these cases have been reported in the news. Human challenge models are studies which allow researchers to study organisms that cause infections in humans. In this human challenge model study, healthy participants will be carefully exposed to a specific type of Strep A under controlled conditions to cause sore throat and learn more about how Strep A causes infection. The study team has already developed a safe human challenge model using a strain of Strep A called M75. This study will use a different strain of Strep A, called M1. The main goal of this study is to check if the procedure is safe for participants and to understand how the participant's body responds to M1 Strep A. The study will explore: 1. How much M1 Strep A is required to cause an infection. 2. How M1 Strep A grows in the body. 3. How the body reacts to M1 Strep A. The information the investigators will get about M1 Strep A from this study will help plan future research. It may also help in designing better studies to test vaccines against Strep A.

NCT Number	NCT06992141
Lead Sponsor	Murdoch Childrens Research Institute Collaborators: University of Auckland, New Zealand, University of Melbourne, University of Wollongong, Université Libre de Bruxelles, University of California, San Diego, Leducq Foundation, National Health and Medical Research Council, Australia, Monash University, Duke University, The University of Queensland, Doherty Clinical Trials Ltd
Conditions	Streptococcus Pyogenes Pharyngitis, Streptococcus Infection
Enrollment	40 participants
Start Date	2025-07-24
Primary Completion	2025-10-31 (estimated)
Study Completion	2026-02-16 (estimated)
Updated on ClinicalTrials.gov	2026-03-16