HD vs SD Quadrivalent Influenza Vaccine in Adults Aged 65 to 79 Years in Galicia

Summary

This pragmatic randomized trial is designed to evaluate the relative vaccine effectiveness of QIV-HD vs. QIV-SD in reducing the risk of hospitalization for influenza or pneumonia in adults 65-79 years of age in Galicia during 2023/2024 and 2024/2025 seasons.

Timeline

Start

2023-10-26

Primary completion

2025-05-31

Completion

2025-05-31

Publications

• Mallah N, Pardo-Seco J, Rodriguez-Tenreiro-Sanchez C, Gine-Vazquez I, Miras-Carballal S, Pineiro-Sotelo M, Cribeiro-Gonzalez M, Conde-Pajaro M, Gonzalez-Perez JM, Razzini JL, Rivero-Calle I, Dacosta-Urbieta AI, Harris RC, Loiacono MM, van Aalst R, Farre JM, Dufournet M, Johansen ND, Modin D, Biering-Sorensen T, Duran-Parrondo C, Martinon-Torres F; GALFLU trial team. Methods and operational framework of GALFLU: Individually randomized pragmatic controlled trial of high- versus standard-dose influenza vaccination in older adults. Vaccine. 2026 Apr 19;79:128435. doi: 10.1016/j.vaccine.2026.128435. Epub 2026 Mar 9.
• Pardo-Seco J, Rodriguez-Tenreiro-Sanchez C, Gine-Vazquez I, Mallah N, Miras-Carballal S, Pineiro-Sotelo M, Cribeiro-Gonzalez M, Conde-Pajaro M, Gonzalez-Perez JM, Rivero-Calle I, Bello X, Razzini JL, Dacosta-Urbieta A, Salas A, Harris RC, Loiacono MM, van Aalst R, Farre JM, Dufournet M, Johansen ND, Modin D, Biering-Sorensen T, Duran-Parrondo C, Martinon-Torres F; GALFLU Trial Team. High-Dose Influenza Vaccine to Reduce Hospitalizations. N Engl J Med. 2025 Dec 11;393(23):2303-2312. doi: 10.1056/NEJMoa2509834. Epub 2025 Aug 30.

Drugs

Indications