NCT06506812

Pooled Analysis of Methodologically Harmonized Pragmatic Randomized Trials of High-Dose vs. Standard-Dose Influenza Vaccine Against Severe Clinical Outcomes

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 466,320 (actual)
• Sponsor: Tor Biering-Sørensen · Academic / Other
• Sex: All
• Age: 65 Years
• Healthy volunteers: Not accepted

Summary

This prespecified analysis will pool the datasets from two pragmatic randomized trials evaluating the relative vaccine effectiveness of high-dose vs. standard-dose influenza vaccine against severe clinical outcomes: the DANFLU-2 (A Pragmatic Randomized Trial to Evaluate the Effectiveness of High-Dose Quadrivalent Influenza Vaccine vs. Standard-Dose Quadrivalent Influenza Vaccine in Older Adults) trial and the GALFLU (Pragmatic Randomized Trial to Evaluate the Effectiveness of High-Dose Quadrivalent Influenza Vaccine vs. Standard-Dose Quadrivalent Influenza Vaccine in Adults Aged 65 to 79 Years in Galicia, Spain) trial. The purpose of the pooled analysis is to ensure adequate statistical power for evaluating relative vaccine effectiveness against severe clinical outcomes and to increase generalizability of the results by combining data from two countries.

Conditions

• Influenza

Interventions

Type	Name	Description
BIOLOGICAL	High-Dose Influenza Vaccine	For this arm, the high-dose quadrivalent influenza vaccine Efluelda®/Fluzone® High-Dose Quadrivalent will be used.
BIOLOGICAL	Standard-Dose Influenza Vaccine	Any standard-dose quadrivalent influenza vaccine administered in the governmental influenza vaccine programs may be used.

Timeline

• Start date: 2025-05-31
• Primary completion: 2025-05-31
• Completion: 2025-08-31
• First posted: 2024-07-18
• Last updated: 2025-09-12

Locations

1 site across 1 country: Denmark