NCT07295028: VXB251-001

Study of an RSV-hMPV-PIV3 Trivalent Vaccine Candidate VXB-251 in Older Adults

Recruiting now Phase 1 Last updated 19 December 2025

What this trial tests

Phase 1 trial testing trivalent (RSV/hMPV/PIV3) vaccine candidate in Lower Respiratory Tract Disease in 240 participants. Currently enrolling.

Timeline

17 November 2025

Primary endpoint
24 May 2026

24 April 2027

Quick facts

Lead sponsor	Vicebio Australia Proprietary Limited
Phase	Phase 1
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	randomized
Design	sequential
Masking	double
Primary purpose	prevention
Enrollment	240
Start date	17 November 2025
Primary completion	24 May 2026
Estimated completion	24 April 2027
Sites	6 locations across Australia

Drugs / interventions tested

• trivalent (RSV/hMPV/PIV3) vaccine candidate — full drug profile →
• trivalent (RSV/hMPV/PIV3) vaccine candidate — full drug profile →
• trivalent (RSV/hMPV/PIV3) vaccine candidate — full drug profile →
• bivalent (RSV/hMPV) unlicensed comparator — full drug profile →
• monovalent (RSV) unlicensed comparator — full drug profile →
• Biological/Vaccine: monovalent (hMPV) unlicensed comparator — full drug profile →
• monovalent (PIV3) unlicensed comparator — full drug profile →
• Placebo

Conditions studied

• Lower Respiratory Tract Disease — all drugs for Lower Respiratory Tract Disease →
• Healthy Participants — all drugs for Healthy Participants →

Sponsor

Vicebio Australia Proprietary Limited — full company profile →

Who can join

Adults 60 to 83, any sex, with Lower Respiratory Tract Disease or Healthy Participants. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

This study is being done to find out how safe and effective a new combined vaccine candidate, called VXB-251, is for older adults. The vaccine candidate is designed to protect against three common viruses that can cause respiratory tract infections:

* RSV (respiratory syncytial virus)
* hMPV (human metapneumovirus)
* PIV3 (parainfluenza virus type 3)

Two components of this vaccine (RSV and hMPV) have already been tested in people before, as part of another study for a two-in-one vaccine. However, this is the first time that the PIV3 component and all three components together (RSV, hMPV, and PIV3) are being tested in people.

The vaccine candidate will be given as a single intramuscular injection. The study will also test unlicensed comparator vaccines and a placebo (a substance that looks like the real vaccine but doesn't contain any active ingredients) that target none, one or two of these viruses to see whether combining all three components affects safety or how well the immune system responds.

Publications & conference data

No peer-reviewed publications indexed yet for this trial.