SGS Strengthens RSV Vaccine Research with Launch of Challenge Agent
A new RSV A-strain challenge agent has been introduced by SGS to enhance CHIM studies and accelerate vaccine development. The breakthrough aims to generate more accurate, data-driven insights into RSV infection and immune response.
Testing and inspecting company, SGS, has announced the launch of a novel Respiratory Syncytial Virus (RSV) A-strain challenge agent, developed to enhance the precision and effectiveness of controlled human infection model (CHIM) studies and accelerate the development and validation of next-generation vaccines and therapeutics (1).
Produced under GMP conditions, the agent 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 through CHIM studies. By safely exposing healthy volunteers to virus strains in a rigorously regulated environment, studies provide powerful early-stage insights into immune protection, allowing companies to make informed “go/no-go” decisions before advancing to costly Phase III trials.
“As a leading European partner in infectious disease and vaccine research, we are delighted to have fulfilled our ambition to accelerate the route to clinical validation of novel RSV therapies and vaccines, bridging preclinical insights to human data through the development of this RSV-A strain challenge agent, the first of its kind worldwide,” said Jelle Klein, Medical Director, SGS, in a company press release (1). “There is an urgent need to ensure that vaccines and therapeutics remain effective, available and affordable for patients. [This] announcement reinforces SGS’s position as a trusted partner, delivering high-quality, decision-enabling data for both pharmaceutical and biotech companies in their pursuit of effective RSV treatment and prevention.”
To demonstrate the agent’s suitability for CHIM use, SGS conducted an early proof-of-concept study at its Clinical Pharmacology Unit in Antwerp, Belgium, where 12 healthy volunteers were inoculated with the RSV-NICA agent and monitored under controlled quarantine conditions for 11 days. Of the 11 participants included in the analysis, nine developed clinically relevant symptoms of RSV infection, and all showed confirmed viral detection by both quantitative polymerase chain reaction (qPCR) and viral culture methods, resulting in a 100% attack rate to validate the inoculation dose and demonstrate the agent’s robust infectivity.
RSV remains a leading cause of serious respiratory illness in infants, older adults, and the immunocompromised, responsible for around 64 million infections and 3 million hospitalizations worldwide each year. Although several vaccines have recently reached the market, researchers continue to seek improved formulations and antiviral options to protect vulnerable populations. SGS’s latest innovation is set to play a pivotal role in evaluating these next-generation candidates before they advance into large-scale clinical trials.
With RSV added to its CHIM portfolio, SGS now offers one of the most comprehensive model suites in Europe, encompassing influenza, rhinovirus, malaria, and RSV. The addition strengthens the company’s capacity to support pharmaceutical and biotech partners in early-phase vaccine and antiviral research to help speed the path toward safer, more effective respiratory disease prevention.
Reference
SGS. RSV Vaccine Research Advances with Launch of Novel A-strain Challenge Agent. Press Release, Dec. 9, 2025.