Introduction:
Controlled human infection models are a platform for studying host-pathogen interactions, preventive, and therapeutic interventions. A meticulous approach to selection, characterisation, and manufacture of challenge agents is critical to volunteer safety. There is no current Australian framework to inform or review these processes. Here, we describe the requirements to manufacture single-dose vials of Streptococcus pyogenes for use in the CHIVAS-M75 pharyngitis human challenge trial.
Methods:
We developed processes to manufacture five dose levels of M75 S. pyogenes in our research facility, according to the principles of Good Manufacturing Practice (GMP). Manufacture was conducted within a biosafety class II cabinet in a restricted-access room. Bacteria were grown in chemically defined ‘animal-free’ media, diluted to strength, dispensed into cryovials, and frozen. Following a single freeze-thaw, rigorous quality control testing proceeded in-house and at an independent laboratory.
Results:
A detailed Batch Manufacturing Record was developed covering all aspects of the manufacture. All five S. pyogenes dose levels complied with specification and were approved for release following an independent review of the documentation, demonstrating the reliability of our workflow.
Conclusion:
We successfully manufactured a bacterial challenge agent at a GMP-like standard within a public research facility at a fraction of the prohibitive costs associated with commercial GMP providers. Our workflow and quality assurance processes can be adapted for other bacteria and other purposes, including manufacture of S. pyogenes reference strains. Our robust approach has contributed to guidelines developed by an international challenge agent manufacturing consortium funded by the Wellcome Trust.