Naobios, a Contract Development and Manufacturing Organization (CDMO) providing bioprocess development and GMP production of clinical batches of virus-based products, and SGS, the world’s leading testing, inspection and certification company, today announce their partnership in the manufacturing of a Respiratory Syncytial Virus (RSV) challenge agent for use in Controlled Human Infection Model (CHIM) studies conducted by SGS.

Produced under cGMP conditions, the Human Viral Challenge Agent (HVCA) is derived from a 2015 A-strain isolate that closely mirrors currently circulating RSV strains, with its realistic infection profile allowing researchers to generate robust, decision-enabling data on vaccine efficacy and immune response dynamics.

Naobios has already successfully completed the development, manufacturing and filling of several HVCAs for study use on the global market. HVCAs are used in strictly controlled clinical trials (or CHIM studies) in which healthy volunteers are intentionally given a carefully considered dose of a pathogen inoculated under rigorous ethical, regulatory and biosafety oversight to evaluate prophylactic vaccines or curative treatments.

These studies enable early and cost-efficient evaluation of RSV vaccines to prevent infection.

To generate first‑in‑human proof-of-concept data, in October 2025 12 healthy participants were inoculated at the SGS Clinical Pharmacology Unit in Antwerp, Belgium, with the RSV A-strain challenge agent. The participants showed a 100% attack rate with mild, self-resolving pathology.

“In response to the growing use of CHIM studies, we have invested to extend our range of services, enabling us to meet the critical needs of clients worldwide,” said Eric Le Forestier, general manager of Naobios. “This partnership with SGS demonstrates that Naobios continues to be a key global player and first-choice partner for viral challenge agent manufacturing in accordance with cGMP.”