NCT06546423

Study of the Infectivity, Safety and Immunogenicity of Two Recombinant, Live-Attenuated, B/HPIV3 Vectored Vaccines Expressing the Fusion Glycoprotein of HMPV Delivered by Nasal Spray to HPIV3-Seropositive Children 24 to <60 Months of Age

Phase I Study of the Infectivity, Safety and Immunogenicity of Two Recombinant, Live-Attenuated, Bovine/Human, Parainfluenza Virus Type 3 (B/HPIV3) Vectored Vaccines Expressing the Fusion Glycoprotein of Human Metapneumovirus (HMPV), Delivered by Nasal Spray to HPIV3-Seropositive Children 24 to <60 Months of Age

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 24 (actual)
• Sponsor: National Institute of Allergy and Infectious Diseases (NIAID) · NIH
• Sex: All
• Age: 24 Months – 59 Months
• Healthy volunteers: Accepted

Summary

HPIV3 and HMPV are viruses that can cause breathing problems in children. The goal of this clinical trial is to look at the safety of 2 experimental HPIV3/HMPV vaccines in HPIV3-seropositive children ≥ 24 months to \< 60 months of age. Children will receive B/HPIV3/HMPV-PreF-A vaccine, B/HPIV3/HMPV-F-B365 vaccine, or placebo, and participants will not know which study product they have received. The main goals of the study are to find out whether these vaccines are well-tolerated and infectious in HPIV3-seropositive children. The general procedures include daily temperature measurements and daily contact with the participant for the first 28 days, giving a single dose of one of the 2 study vaccines or placebo delivered by nasal sprayer, about 9 in-person visits, a physical examination, 7 clinical assessments, 2 blood samples, 9 nasal swabs and monthly contacts with the participant between Days 29-180. Additional visits may occur if the child has a respiratory illness, fever, or ear infections. The illness visit will include a nasal swab and a clinical assessment.

Detailed description

This is a blinded, randomized, placebo-controlled study design will be used to evaluate the safety and immunogenicity of the study product in HPIV3-seropositive participants. The study will be performed in approximately 25 HPIV3-seropositive children ≥ 24 months to \< 60 months of age. Subjects will be block randomized to receive a single dose of 10\^5.6 PFU of B/HPIV3/HMPV-PreF-A, 10\^5.6 PFU of B/HPIV3/HMPV-F-B365, or placebo in a 2:2:1 ratio. Enrollment will be continuous unless stopping rules are met or other safety concerns occur. During the enrollment period, the Data and Safety Monitoring Board (DSMB) will perform unblinded safety reviews. After completion of the Day 28 visit of the last participant, an unblinded review of all participants will be performed by the DSMB. The first 28 days after inoculation are considered the Acute Phase of the study, and the participants' parents/guardians will be contacted daily during the Acute Phase. These contacts will consist either of an in-person evaluation of interim medical history, clinical assessment, and nasal swab, or an interim medical history conducted by a mutually agreed upon communication method. If a child develops a respiratory or febrile illness or otitis media during the acute phase, an in-person evaluation will be performed. During the Acute Phase, the participants will be evaluated for adverse events (AEs) or serious adverse events (SAEs). Between Days 29 and 180 parents/guardians will be asked to contact study staff to report Medically Attended Adverse Events (MAAEs), which will be reported per protocol. Between days 29-180, study staff will contact the participants' parents/guardians monthly and on Day 180 (±7 days) after inoculation to capture any previously unreported MAAEs. Clinical assessments will be completed and nasal swabs will be obtained on study Days 0, 3, 4, 5, 6, 7, 10, 14 and 28 and whenever febrile or respiratory illnesses or otitis media (solicited AEs) are reported during the first 28 days following inoculation. The nasal swab will be tested for vaccine virus, for respiratory pathogens that are considered adventitious agents, including wild-type HPIV3 and HMPV, and for mucosal IgG and IgA antibody as listed in the schedule of events.

Conditions

• Human Metapneumovirus
• Human Parainfluenza Virus Type 3

Interventions

Type	Name	Description
BIOLOGICAL	B/HPIV3/HMPV-PreF-A vaccine	B/HPIV3/HMPV-PreF-A is a live-attenuated vaccine candidate. The B/HPIV3/HMPV-PreF-A vaccine is provided in a sterile 2.0-mL cryovial, each containing 0.6 mL of vaccine with a titer of approximately 10\^6.7 PFU/mL. The vaccine virus concentrate is diluted with Lactated Ringer's Solution for Injection to a dose of approximately 10\^5.6 PFU in a 0.2 mL volume.
BIOLOGICAL	B/HPIV3/HMPV-F-B365 vaccine	B/HPIV3/HMPV-F-B365 is a live-attenuated vaccine candidate. The B/HPIV3/HMPV-F-B365 vaccine is provided in a sterile 2.0-mL cryovial, each containing 0.6 mL of vaccine with a titer of approximately 10\^6.3 PFU/mL. The vaccine virus concentrate is diluted with Lactated Ringer's Solution for Injection to a dose of approximately 10\^5.6 PFU in a 0.2 mL volume.
DRUG	Placebo	Lactated Ringer's Injection, USP is a sterile, nonpyrogenic solution for fluid and electrolyte replenishment. It will be drawn up in a sterile syringe to a volume of 0.2 mL.

Timeline

• Start date: 2024-07-12
• Primary completion: 2025-06-04
• Completion: 2025-06-04
• First posted: 2024-08-09
• Last updated: 2026-04-16

Locations

4 sites across 1 country: United States

Regulatory

• FDA-regulated drug study