Covid-19 Challenge Models

hVIVO’s COVID‑19 Human Challenge Model provides controlled evaluation of next‑generation vaccines and therapeutics to generate rapid, high‑resolution efficacy data

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The Challenge

Coronaviridae commonly cause mild respiratory illness but emerging strains such as SARS and MERS can cause severe disease. In December 2019, SARS‑CoV‑2 emerged in Wuhan, leading to the COVID‑19 pandemic, over 500M infections and 6M deaths. Despite approved vaccines and treatments, new variants highlight the need for vaccines preventing transmission and more effective therapeutics.

Efficacy testing of next‑generation vaccines in a controlled setting
Relative protective efficacy benchmarking using licensed vaccines
Assessment of vaccination impact on viral shedding (transmission blockade)
Comparative efficacy across vaccine platforms
Validation of vaccine‑mediated correlates of protection
Accelerated optimisation of vaccine dosing and regimen
Evaluation of booster regimens against variants of concern (VOCs)

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Why Consider hVIVO?

hVIVO conducted the world’s first human viral SARS-CoV-2 challenge model. hVIVO was the prime contractor appointed to the UK government during the pandemic to set up a SARS-CoV-2 challenge model as part of a pandemic response to ensure the model was available to help select vaccines if the first generation vaccines were not successful. Whilst the UK government set up the delivery group as a consortium, hVIVO was the lead contractor and responsible for all of the following:

production and release of the challenge agent
set up of the clinical site
preparation of protocol and ethics submission package
100% of the screening and clinical conduct of the challenge study
provision of the study PIs
sample collection and processing
conduct of all virological and molecular based analytical assessments
data management and reporting.

The study was designed in collaboration with leading UK academics and additional safety oversight provided in the form of the CI from UK government appointed Imperial College as well as an external data safety monitoring board (DSMB).

The original pre-alpha SARS-CoV-2 strain that was characterized in immunologically naïve participants prior to wide spread vaccine rollout in the pandemic. hVIVO then produced a Delta strain under contract for others and have also now developed a BA5 Omicron model virus that we have characterized in previously vaccinated, antibody positive participants ready for booster vaccine and antiviral efficacy testing.

FAQ

What is the COVID19 Human Challenge Model?

The COVID19 Human Challenge Model is a controlled clinical research model that enables precise evaluation of next generation COVID19 vaccines and therapeutics to generate rapid, high resolution efficacy data.

Why are COVID19 human challenge studies still needed?

Despite approved vaccines and treatments, new SARSCoV2 variants continue to emerge. This drives the ongoing need for vaccines that better prevent transmission and therapeutics that provide broader and more durable protection.

What scientific questions can this model help answer?

The model assesses:

Efficacy of nextgeneration vaccines in a controlled environment.
Benchmarking of protective efficacy using licensed vaccines.
The impact of vaccination on viral shedding and transmission.
Comparative efficacy across vaccine platforms.
Validation of correlates of protection.
Optimisation of vaccine dose and regimen.
Evaluation of booster regimens against variants of concern.

How does a controlled challenge model accelerate vaccine development?

Controlled exposure allows rapid measurement of infection, viral kinetics, immune response, and protection—without waiting for natural community transmission. This can substantially shorten development timelines for next generation vaccines and therapeutics.

Can the model be used to evaluate variant specific or booster vaccines?

Yes. The model includes the capability to evaluate booster regimens and candidate vaccines against variants of concern (VOCs).

What makes this model suitable for studying viral transmission?

It enables direct assessment of viral shedding following controlled exposure, helping researchers understand whether candidate vaccines can block transmission.

How can the data generated support regulatory interactions?

By providing high resolution efficacy, viral kinetics, and correlates of protection data, the model supports evidence packages for regulatory submissions and strategic decision making during vaccine and therapeutic development.

Who typically uses the COVID19 Human Challenge Model?

The model is designed for vaccine developers, antiviral drug programmes, biotechnology companies, and government or global health organisations seeking rapid comparative data on emerging COVID19 countermeasures.

Covid-19 Challenge Models

The Challenge

"Valuable scientific input and support from clinician"

The challenge model as a solution

Why Consider hVIVO?

FAQ

Related Resources

From RSV to hMPV: Building the Next Generation of Respiratory Challenge Models

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Unravelling the hMPV Surge: From Media Attention to Vaccine Development

Why are Biotech’s & Pharma Using Human Challenge Studies for Drug Development?

Tripledemic Takedown: How Human Challenge Trials are Ideal to Expedite Multivalent Vaccine Development

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Human Challenge Studies: Their Conduct and Safety Aspects

Human Challenge Trials as a tool in raising funding

UK Life Sciences Sector Plan 2025: What it Means for the Future of Clinical Research

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