NCT06613737

Dose, Safety, and Pathogenicity of a New Influenza A H3N2 Challenge Strain

An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a New Influenza A H3N2 Challenge Strain in Healthy Participants 18 to 55 Years of Age

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 33 (actual)
• Sponsor: Hvivo · Industry
• Sex: All
• Age: 18 Years – 55 Years
• Healthy volunteers: Accepted

Summary

An Exploratory Study to Establish the Dose, Safety and Pathogenicity of a New Influenza A H3N2 Challenge Strain in Healthy Participants 18 to 55 Years of Age In Part A, up to 40 participants will be randomly allocated to one of two groups to be given one of two virus doses (Virus Dose 1 or Virus Dose 2). Based on the outcome of Part A, participants in Part B, may be given Virus Dose 1, Virus Dose 2, or another virus dose (e.g., Virus Dose 3)

Detailed description

This is an exploratory study of an influenza A/England/7763/2022 H3N2 challenge strain, to determine the optimum safe infectious titer of challenge agent, in healthy participants 18 to 55 years of age. A total of up to 80 participants may be given the influenza A/England/7763/2022 H3N2 challenge agent. Each participant will remain in the study for approximately 4 months from screening to the last clinic visit. The study will consist of 2 parts, in Part A of the study, up to 40 participants will be randomly allocated to one of two groups to be given one of two virus doses (Virus Dose 1 or Virus Dose 2). Based on the outcome of Part A, additional participants may be enrolled into the optional Part B of the study and may be given Virus Dose 1, Virus Dose 2, and/or another virus dose (e.g., Virus Dose 3) The study is divided into three phases: 1. Screening phase: Screening will occur between Day -90 to Day -2/-1. 2. Quarantine phase: Participants will stay in the quarantine unit for approximately 8 days (from Day -2/-1 to Day 8). 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 8 (or may remain longer at the principal investigator's discretion). 3. Outpatient phase: Following the conclusion of the quarantine phase, participants will attend a Follow-Up visit, approximately 28 days after they received the study virus. Their symptoms will be reassessed, and a complete safety examination performed.

Conditions

• Influenza A H3N2

Interventions

Type	Name	Description
OTHER	Influenza A H3N2 virus dose arm 1	Medium dose, approximately 10\^4.5 TCID50/mL
OTHER	Influenza A H3N2 virus dose arm 2	High dose, approximately 10\^5.5 TCID50/mL
OTHER	Influenza A H3N2 virus dose arm 3	TBD, depending on outcome of Part A

Timeline

• Start date: 2024-09-11
• Primary completion: 2025-03-10
• Completion: 2025-03-10
• First posted: 2024-09-26
• Last updated: 2025-08-22

Locations

1 site across 1 country: United Kingdom