A Randomized Phase 1 Clinical Trial of a Respiratory Syncytial Virus and Human Metapneumovirus Combination Protein-Based Virus-like Particle Vaccine in Adults 60-75 Years of Age.
Summary
In a randomized Phase 1 study of adults aged 60–75 years, a combination RSV/hMPV protein-based VLP vaccine (IVX-A12) was well tolerated and boosted neutralizing antibodies against both viruses up to 3–5-fold by day 28, with responses persisting to day 365. No vaccine-related serious adverse events were observed.
Key Findings
- Randomized Phase 1 trial in adults 60–75 years evaluated IVX-A12 at multiple dose levels ± MF59 vs placebo.
- Well tolerated with only mild-to-moderate transient reactions; no vaccine-related serious adverse events.
- Neutralizing antibody titers increased up to 4× (RSV A), 3× (RSV B), 5× (hMPV A), and 4× (hMPV B) by day 28, with responses maintained around/above baseline through day 365.
Clinical Implications
Although early-phase, the data support advancing combination RSV/hMPV vaccination strategies for older adults pending efficacy trials, potentially simplifying immunization schedules.
Why It Matters
Demonstrates safety and dual-pathogen immunogenicity of a combination respiratory virus vaccine in older adults, supporting development of broader LRTD prevention strategies.
Limitations
- Phase 1 study not powered for clinical efficacy against LRTD
- Immunogenicity endpoints limited to neutralizing antibodies without cellular immunity detail in abstract
Future Directions
Proceed to Phase 2/3 efficacy trials in older adults, assess durability, correlates of protection, and potential coadministration with other vaccines.
Study Information
- Study Type
- RCT
- Research Domain
- Prevention
- Evidence Level
- II - Randomized Phase 1 trial demonstrating safety and immunogenicity
- Study Design
- OTHER