Safety and Immunogenicity of Different Formulations of an MF59-Adjuvanted Influenza Vaccine in Older Adults ≥50 Years of Age

Summary

This Phase 2, randomized, observer-blind, dose-confirmation clinical study evaluated different formulations of MF59-Adjuvanted Quadrivalent Subunit Inactivated Influenza Vaccine. Approximately 1000 subjects were randomized into 1 of 4 possible treatment groups with approximately 250 participants per group. Every participant received an influenza vaccine injection on Day 1 and were to be followed up for approximately 6 months following injection. The primary immunogenicity analysis is based on Day 29 serology data.

Timeline

Start

2022-08-25

Primary completion

2023-03-31

Completion

2023-03-31

Outcome

Met primary endpoint

paper were superior (lower limit of 95% CI >1.0) for all strains. PMID 41855648 ↗

paper GMTr of aQIVc [45,2×] vs. QIVc [45,0×] were superior for A/H1N1, A/H3N2, and B/Yamagata, and non-inferior for B/Victoria. PMID 41855648 ↗

Publications

• de Looze F, Essink BJ, van Boxmeer J, Andrade C, de Rooij R, Casula D, Xing R, Tovar MP, Albano FR. Immunogenicity and safety of higher-dose cell-based adjuvanted quadrivalent influenza vaccines: Combined results of randomised, controlled dose-finding and dose-confirmation studies. Vaccine. 2026 Apr 19;79:128436. doi: 10.1016/j.vaccine.2026.128436. Epub 2026 Mar 19.

Drugs

Evaluation	Drug	Modality	Dose	Route
Subject	IIV-A	Vaccine	—	Intramuscular
Comparator	Licensed IIV	Vaccine	—	Intramuscular
Subject	aIIV-B	Vaccine	—	Intramuscular
Subject	aIIV-C	Vaccine	—	Intramuscular

Indications