Exploring a new influenza B strain's safety and dosage

An Exploratory Study To Establish The Dose, Safety, And Pathogenicity Of A New Influenza B Challenge Strain In Healthy Participants 18 To 55 Years Of Age

Phase 2 Interventional Hvivo · NCT06254820

This study is testing the safety and right amount of a new flu B virus in healthy adults aged 18 to 55 to see how it affects them.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment60 (estimated)
Ages18 Years to 55 Years
SexAll
SponsorHvivo Industry-sponsored
Locations1 site (London)
Trial IDNCT06254820 on ClinicalTrials.gov

What this trial studies

This exploratory study investigates the safety and optimal infectious dose of a new influenza B challenge strain in healthy adults aged 18 to 55. Up to 80 participants will be enrolled and divided into two parts, where they will receive different doses of the virus. The study includes a screening phase, a quarantine phase lasting approximately 11 days, and outpatient follow-up. Participants will undergo clinical assessments and safety monitoring throughout their time in quarantine.

Who should consider this trial

Good fit: Ideal candidates are healthy adults aged 18 to 55 with a body weight of at least 50 kg and a BMI between 18 and 35.

Not a fit: Patients with a history of respiratory infections or significant medical conditions may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to improved understanding and management of influenza B infections.

How similar studies have performed: Other studies have successfully explored similar challenge strains, indicating potential for this approach.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Written informed consent
* Adult male or female aged between 18 and 55 years
* A total body weight ≥50 kg and body mass index (BMI) ≥18 kg/m2 and ≤35kg/m2
* 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.

Exclusion Criteria:

* 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 ≥10 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.
* Lifetime history of anaphylaxis and/or a lifetime history of severe allergic reaction.
* Venous access deemed inadequate for the phlebotomy and cannulation demands of the study.
* Significant abnormality of the nose, epistaxis, nasal or sinus surgery.
* Recent vaccinations or intention to receive vaccination before the final follow up visit.
* 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 ≥37.9C 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

Where this trial is running

London

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Influenza BInfluenzaFluHuman Challenge TrialsFlu B
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.