Open Orphan plc changed its name to hVIVO plc on 26 October 2022, learn more here.

Human Challenge Models

Challenge models that expedite and inform clinical development

The world leader in conducting human challenge trials in infectious and respiratory disease

Building on decades of unrivalled experience, hVIVO is currently the only CRO focused on challenge studies, providing world class expertise and capabilities in challenge agent manufacture, a unique portfolio of established human challenge models to test a broad range of infectious and respiratory disease products, and specialist drug development and clinical consultancy services.

See the number of subjects inoculated for our
viral challenge models:






(Wuhan, Delta, Omicron)




Why do a Human Challenge Trial?

Flu virus

Generates invaluable dosing, safety and efficacy data

Helps optimise for larger field trials

Clinical Development

Requires fewer subjects

Significant time savings

De-risk Phase III program


Potential for Fast Track or Break Through designation

Potential approval and Emergency Use Authorisation


Significant valuation uplift for Biotech sponsor

Allows products to "Succeed fast" or "Fail Fast"

Full-Service Solution:

Our Human Challenge Trials are an ideal tool to provide early efficacy data for your vaccine and drugs in infectious diseases

Our drug development consultancy services support the development of your product throughout the lifecycle

Discover our study design & methodology services to optimalise the design of your trial

Ethics & Regulatory

Discover our offering to support your phase 1 & phase 2 clinical trials

Our dedicated recruitment team offers tailormade trial recruitment solutions and has a wealth of experience in recruiting special populations

Out London site has all the assets to be part of your multi-center patient trial


Our data management & statistics solutions offer you a quick and efficient biometric solutions for your clinical trial

A broad suite of services to support non-clinical and clinical respiratory drug and vaccine discovery and development

Our team develops a broad range of regulatory documents: from Scientific Advice briefing packages over IND submission documents to clinical study reports

World leader in testing infectious and respiratory disease products using human challenge clinical trials

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If you’re a potential customer, job seeker, health professional or an investor, find out how hVIVO can help you.

Contact hVIVO