SARS-CoV-2 InfectionEarly Phase 1NCT06492564
Dose, Safety and Pathogenicity of SARS-CoV-2 (COVID-19) Omicron Virus (BA.5)
A Early Phase 1 study testing SARS-CoV-2 omicron virus dose arm 1, SARS-CoV-2 omicron virus dose arm 2 and SARS-CoV-2 omicron virus dose arm 3 in people with SARS-CoV-2 Infection, run by Hvivo at 1 site in United Kingdom.
Trial summary
An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a SARS-CoV-2 Omicron Challenge Strain (BA.5) in Healthy Participants 18 to 40 Years of Age Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- SARS-CoV-2 Infection
- What is being tested?
- SARS-CoV-2 omicron virus dose arm 1, SARS-CoV-2 omicron virus dose arm 2 and SARS-CoV-2 omicron virus dose arm 3
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 2 Dec 2024to 16 Oct 2025
- Phase
- Early Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Written informed consent
- Adult male or female aged between 18 and 40 years
- A total body weight ≥50 kg and body mass index (BMI) ≥18 kg/m2 and ≤28kg/m2. The upper limit of BMI may be increased to ≤30kg/m2 at the PI's discretion, in the case of physically fit muscular individuals.
- In good health with no history, or current evidence, of clinically significant medical conditions, and no clinically significant test abnormalities that will interfere with participant safety.
- Documented medical history
- Adherence to contraception requirements
- Serosuitable for the challenge virus
- Participants must have been previously vaccinated with a COVID-19 vaccine licensed for use in the UK and completed the course
Who cannot join
- History of, or currently active, symptoms or signs suggestive of upper or lower respiratory tract (LRT) infection within 4 weeks prior to the first study visit.
- Any history or evidence of any clinically significant or currently active disease.
- Any participants who have smoked ≥5 pack years at any time.
- Female participants who are breastfeeding, or have been pregnant within 6 months prior to the study, or have a positive pregnancy test at any point during screening or prior to inoculation.
- Any history of anaphylaxis and/or a any history of severe allergic reaction.
- Venous access deemed inadequate for the phlebotomy and cannulation demands of the study.
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- History of severe COVID-19 or severe complication of any other viral disease.
- Participants with no knowledge of their family history, as deemed appropriate by the PI
- Significant abnormality of the nose, includes loss of or alterations in smell or taste,nasal polyps, epistaxis, nasal or sinus surgery.
- Recent vaccinations or intention to receive vaccination before the Day 28 follow up visit. Receipt of COVID-19 vaccine in the last 3 months prior to inoculation and/or a diagnosis of COVID 19 confirmed by a physician within the last 6 months prior to screening or at any time between screening and quarantine admission.
- Receipt of blood or blood products, or loss (including blood donations) of 550 mL or more of blood during the 3 months prior to the planned inoculation or planned during the 3 months after the final visit.
- Recent receipt of investigational drugs or challenge viruses.
- Use or anticipated use during the conduct of the study of concomitant medications (prescription and/or non-prescription), including vitamins or herbal and dietary supplements within the specified windows.
- Positive drugs of abuse test or recent history or presence of alcohol addiction
- A forced expiratory volume in 1 second (FEV1) <80%.
- Positive HIV, hepatitis B virus, or hepatitis C virus test.
- Presence of fever, defined as participant presenting with a temperature reading of ≥37.9°C on Day -2/-1 and/or pre-inoculation on Day 0.
- Those employed or immediate relatives of those employed at hVIVO or the sponsor.
- Any other reason, in the opinion of the investigator deems the participant unsuitable for the study
- Sensitivity to any of the study interventions, challenge agent or components thereof (including lactose), or drug or other allergy that, in the opinion of the PI/investigator, contraindicates participation in the study.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
hVIVO Services Ltd, 40 Bank Street, Canary Wharf
London, E14 5NR
About this study
Official title: An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a SARS-CoV-2 Omicron Challenge Strain (BA.5) in Healthy Participants 18 to 40 Years of Age
An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a SARS-CoV-2 Omicron Challenge Strain (BA.5) in Healthy Participants 18 to 40 Years of Age
Read the detailed description
This is an exploratory study of an SARS-CoV-2 Omicron (BA.5) challenge strain to determine the optimum safe infectious titer of challenge agent in healthy participants 18 to 40 years of age.
Up to 90 participants who meet all study inclusion and no exclusion criteria will be allocated to one of the three dose escalating cohorts (Dose 1, Dose 2 or Dose 3), with up to 30 participants in each dose group, to receive one dose of SARS-CoV-2 omicron. Based on the outcome of each cohort the next cohort may receive a high or lower dose than the previous cohort.
Each participant will remain in the study for approximately 9 months from screening to the last clinic visit.
The study is divided into three phases:
- Screening phase: Screening will occur between Day -90 to Day -2/-1.
- Quarantine phase: Participants will stay in the quarantine unit for approximately 17 days (from Day -2/-1 to Day 14). One or two days prior to the day of inoculation with the challenge virus, participants will be admitted to quarantine where their eligibility will be reassessed. If participants remain eligible for the study, they will receive the challenge virus on Day 0. Participants will undergo a range of clinical assessments and safety monitoring for the entirety of their stay in quarantine. Participants will be discharged from the quarantine unit on Day 14 (or may remain longer at the principal investigator's discretion). If participants do not become infected with the virus they may be discharged earlier on Day 8.
- Outpatient phase:Following the conclusion of the quarantine phase, participants will receive telephone follow up calls every 3 days between quarantine discharge and the day 28 follow up visit. Participants will also attend additional Follow-Up visits, approximately 28 days, 90 days, and 180 days after they received the study virus. Their symptoms will be reassessed, and a complete safety examination performed.
- Conditions
- SARS-CoV-2 Infection
- Being tested
- SARS-CoV-2 omicron virus dose arm 1, SARS-CoV-2 omicron virus dose arm 2, SARS-CoV-2 omicron virus dose arm 3
- Keywords
- SARS-CoV-2, Omicron, COVID-19, Human Challenge Trials
- Medical subject headings
- COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
SARS-CoV-2 omicron virus dose arm 1Biological
Low dose, approximately 10^4 TCID50/mL
SARS-CoV-2 omicron virus dose arm 2Biological
Medium dose, approximately 10^5 TCID50/mL
SARS-CoV-2 omicron virus dose arm 3Biological
High dose, approximately 10^6 TCID50/mL
| Study group | Role | What they receive |
|---|---|---|
| Dose 1 | Experimental | Low dose, expected to be approximately 10^4 tissue culture infective dose 50% (TCID50)/mL (titer may be adjusted based on stock titer) Receives: Biological: SARS-CoV-2 omicron virus dose arm 1 |
| Dose 2 | Experimental | Medium dose, expected to be approximately 10^5 tissue culture infective dose 50% (TCID50)/mL (titer may be adjusted based on stock titer) Receives: Biological: SARS-CoV-2 omicron virus dose arm 2 |
| Dose 3 | Experimental | High dose, expected to be approximately 10^6 tissue culture infective dose 50% (TCID50)/mL (titer may be adjusted based on stock titer) Receives: Biological: SARS-CoV-2 omicron virus dose arm 3 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Occurrence of Adverse Events related to the viral challenge
Number of participants with challenge Agent-emergent adverse events (AEs) at least possibly related to the viral challenge from viral challenge (Day 0) up to the Day 28 follow-up
Measured: Day 0 to Day 28
Occurrence of Serious Adverse Events and Medically Attended Adverse Events, related to the viral challenge
Occurrence of serious AEs (SAEs) and Medically Attended Adverse Events (MAAEs) related to the viral challenge from viral challenge (Day 0) up to the Day 180 follow-up
Measured: Day 0 to Day 180
Induces laboratory-confirmed infection in ≥40% of inoculated participants
Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR)-confirmed SARS-CoV-2 omicron infection, defined as 2 quantifiable (≥ lower limit of quantification [LLOQ]) qRT-PCR measurements (reported over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 14 am).
Measured: Day 1 to Day 14
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jul 2024
- Study start2 Dec 2024
- Primary completion16 Oct 2025
- Study completion16 Oct 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for SARS-CoV-2 InfectionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hvivo
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Melissa Bevan, MBBS, Principal investigator, hVIVO Services Ltd.
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06492564
- Sponsor's protocol ID
- HRD-vCS-003
- Status last verified
- Oct 2025
- First submitted
- 5 Jul 2024
- Last updated
- 21 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a SARS-CoV-2 Omicron Challenge Strain (BA.5) in Healthy Participants 18 to 40 Years of Age
- ClinicalTrials.gov ID
- NCT06492564
- Acronym / sponsor ID
- HRD-vCS-003
- Conditions
- SARS-CoV-2 Infection
- Keywords
- SARS-CoV-2, Omicron, COVID-19, Human Challenge Trials
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 36 participants (actual)
- Lead sponsor
- HvivoIndustry (pharma, biotech, devices)
- Study start
- 2 Dec 2024 (actual)
- Primary completion
- 16 Oct 2025 (actual)
- Study completion
- 16 Oct 2025 (actual)
- First posted
- 9 Jul 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a SARS-CoV-2 Omicron Challenge Strain (BA.5) in Healthy Participants 18 to 40 Years of Age
Detailed description
This is an exploratory study of an SARS-CoV-2 Omicron (BA.5) challenge strain to determine the optimum safe infectious titer of challenge agent in healthy participants 18 to 40 years of age.
Up to 90 participants who meet all study inclusion and no exclusion criteria will be allocated to one of the three dose escalating cohorts (Dose 1, Dose 2 or Dose 3), with up to 30 participants in each dose group, to receive one dose of SARS-CoV-2 omicron. Based on the outcome of each cohort the next cohort may receive a high or lower dose than the previous cohort.
Each participant will remain in the study for approximately 9 months from screening to the last clinic visit.
The study is divided into three phases:
- Screening phase: Screening will occur between Day -90 to Day -2/-1.
- Quarantine phase: Participants will stay in the quarantine unit for approximately 17 days (from Day -2/-1 to Day 14). One or two days prior to the day of inoculation with the challenge virus, participants will be admitted to quarantine where their eligibility will be reassessed. If participants remain eligible for the study, they will receive the challenge virus on Day 0. Participants will undergo a range of clinical assessments and safety monitoring for the entirety of their stay in quarantine. Participants will be discharged from the quarantine unit on Day 14 (or may remain longer at the principal investigator's discretion). If participants do not become infected with the virus they may be discharged earlier on Day 8.
- Outpatient phase:Following the conclusion of the quarantine phase, participants will receive telephone follow up calls every 3 days between quarantine discharge and the day 28 follow up visit. Participants will also attend additional Follow-Up visits, approximately 28 days, 90 days, and 180 days after they received the study virus. Their symptoms will be reassessed, and a complete safety examination performed.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Sequential
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Dose 1 | Experimental | Biological: SARS-CoV-2 omicron virus dose arm 1Low dose, expected to be approximately 10^4 tissue culture infective dose 50% (TCID50)/mL (titer may be adjusted based on stock titer) |
| Dose 2 | Experimental | Biological: SARS-CoV-2 omicron virus dose arm 2Medium dose, expected to be approximately 10^5 tissue culture infective dose 50% (TCID50)/mL (titer may be adjusted based on stock titer) |
| Dose 3 | Experimental | Biological: SARS-CoV-2 omicron virus dose arm 3High dose, expected to be approximately 10^6 tissue culture infective dose 50% (TCID50)/mL (titer may be adjusted based on stock titer) |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Written informed consent
- Adult male or female aged between 18 and 40 years
- A total body weight ≥50 kg and body mass index (BMI) ≥18 kg/m2 and ≤28kg/m2. The upper limit of BMI may be increased to ≤30kg/m2 at the PI's discretion, in the case of physically fit muscular individuals.
- In good health with no history, or current evidence, of clinically significant medical conditions, and no clinically significant test abnormalities that will interfere with participant safety.
- Documented medical history
Key exclusion criteria (20 listed)
- History of, or currently active, symptoms or signs suggestive of upper or lower respiratory tract (LRT) infection within 4 weeks prior to the first study visit.
- Any history or evidence of any clinically significant or currently active disease.
- Any participants who have smoked ≥5 pack years at any time.
- Female participants who are breastfeeding, or have been pregnant within 6 months prior to the study, or have a positive pregnancy test at any point during screening or prior to inoculation.
- Any history of anaphylaxis and/or a any history of severe allergic reaction.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| SARS-CoV-2 omicron virus dose arm 1Low dose, approximately 10^4 TCID50/mL | Biological | Dose 1 |
| SARS-CoV-2 omicron virus dose arm 2Medium dose, approximately 10^5 TCID50/mL | Biological | Dose 2 |
| SARS-CoV-2 omicron virus dose arm 3High dose, approximately 10^6 TCID50/mL | Biological | Dose 3 |
Primary outcome
Occurrence of Adverse Events related to the viral challenge
Time frame: Day 0 to Day 28
Number of participants with challenge Agent-emergent adverse events (AEs) at least possibly related to the viral challenge from viral challenge (Day 0) up to the Day 28 follow-up
Occurrence of Serious Adverse Events and Medically Attended Adverse Events, related to the viral challenge
Time frame: Day 0 to Day 180
Occurrence of serious AEs (SAEs) and Medically Attended Adverse Events (MAAEs) related to the viral challenge from viral challenge (Day 0) up to the Day 180 follow-up
Induces laboratory-confirmed infection in ≥40% of inoculated participants
Time frame: Day 1 to Day 14
Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR)-confirmed SARS-CoV-2 omicron infection, defined as 2 quantifiable (≥ lower limit of quantification [LLOQ]) qRT-PCR measurements (reported over 4 planned consecutive assessments within 48 hours), from Day 1 pm to planned discharge from quarantine (Day 14 am).
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Nov 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Melissa Bevan, MBBS principal investigator
hVIVO Services Ltd.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing SARS-CoV-2 omicron virus dose arm 1, SARS-CoV-2 omicron virus dose arm 2 and SARS-CoV-2 omicron virus dose arm 3 in people with SARS-CoV-2 Infection, run by Hvivo at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 20 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Occurrence of Adverse Events related to the viral challenge (time frame: Day 0 to Day 28). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Nov 2025.