Controlled Human Infection Studies (CHIS) have proven to be essential in exploring human responses to respiratory infections and testing the effectiveness of vaccines and treatments. These studies hinge on selecting an appropriate challenge virus, making a diverse panel of strains indispensable for tailored research goals. Aiming to bolster the tools available for influenza studies, hVIVO has introduced a panel of challenge strains representing the three dominant influenza subtypes: H3N2, H1N1, and influenza B. Each strain underwent rigorous development and clinical evaluation to ensure its utility in advancing research efforts.
The virus selection process relied on clinical samples from recent infections, which were meticulously triaged for viability and suitability. From these, selected strains underwent further development to create seed virus banks using Good Manufacturing Practice (GMP) protocols. Each strain’s production included sterility checks and genetic testing to ensure quality and integrity. This robust process resulted in three strains: H1N1 (A/France/759/2021), H3N2 (A/England/7763/2022), and influenza B (B/Connecticut/01/2001), each now available for use in clinical settings.
In the clinical studies, healthy volunteers aged 18–45 were inoculated with these viruses, with outcomes closely monitored through symptom diaries, nasopharyngeal swabs, and various safety assessments. The results were promising, particularly for the H1N1 and B strains, which demonstrated high infection rates, significant viral loads, and notable symptom profiles. These findings underline the panel’s effectiveness in producing observable febrile illness and strong systemic responses, crucial for testing new interventions.
Safety assessments revealed no serious adverse events, and while some participants experienced temporary neutropenia and lymphopenia, these conditions resolved quickly. The strains showcased excellent profiles for use in human challenge studies, marking a significant step forward in influenza research. By employing this new panel, researchers can explore vaccine efficacy and antiviral treatments more effectively, ensuring relevance to contemporary circulating strains.
The development of these influenza challenge agents reflects a significant advance in creating precise tools for studying influenza and testing new medical interventions. With high infection rates and safety assurances, this panel paves the way for more targeted and impactful research, offering invaluable resources for combating the challenges posed by influenza.
hVIVO plc (formerly Open Orphan plc), led by Cathal Friel, is a rapidly growing specialist contract research organisation (CRO) and the world leader in testing infectious and respiratory disease vaccines and antivirals using human challenge clinical trials, providing end-to-end early clinical development services for its broad and long-standing client base of biopharma companies.
