Sanofi announced that its high-dose influenza vaccine, marketed as Efluelda in Europe and Fluzone High-Dose in North America, has shown greater effectiveness in reducing hospitalizations among adults aged 65 and older compared to standard-dose influenza vaccines. The findings come from the FLUNITY-HD study, which is described as the largest individually randomized study of older adults for influenza vaccine effectiveness, involving nearly half a million participants across several flu seasons and two geographic regions.
According to the data published in The Lancet, the high-dose vaccine reduced laboratory-confirmed influenza hospitalizations by an additional 31.9% compared to standard-dose vaccines. It also provided further protection against hospitalizations due to pneumonia or influenza, cardio-respiratory events, and all-cause hospitalizations in the older adult population.
“The FLUNITY-HD study, unparalleled in its design and scale, harnesses the power and scientific rigor of individual randomization in real-world settings,” said Professor Tor Biering-Sørensen, Cardiologist, Chief Investigator, and sponsor of the FLUNITY-HD study. “This first-of-its-kind study assessed the benefits of the high-dose influenza vaccine against severe outcomes compared to standard-dose, including against cardio-respiratory hospitalizations, in a randomized setting, covering two geographic areas. The results provide critical evidence, potentially reshaping public health strategies and clinical guidelines.”
Professor Federico Martinon-Torres, Co-Principal Investigator of FLUNITY-HD study, stated, “This new evidence reinforces the clinical confidence healthcare professionals have that the high-dose influenza vaccine achieves superior protection over standard-dose against severe outcomes in older adults, a group considered vulnerable due to having a weakened immune system and a higher risk of developing serious complications after flu infection.”
Sanofi’s Global Head of Medical for Vaccines, Bogdana Coudsy, MD, commented on the broader implications: “Adults 65 and older represent up to 70% of flu hospitalizations. The FLUNITY-HD data confirm that our high-dose flu vaccine provides superior protection against hospitalizations compared to standard-dose vaccines in older adults. For every 515 older adults who receive our high-dose flu vaccine instead of standard-dose vaccines, one all-cause hospitalization is prevented. This can mean a lot, especially for vulnerable seniors, decreasing the burden on their quality of life and helping them to maintain their autonomy for longer. Additionally, preventing influenza hospitalizations may bring societal benefits such as lower healthcare costs, less pressure on medical systems, and reduced burden on caregivers.”
The FLUNITY-HD study is based on a pooled analysis of two randomized trials—DANFLU-2 in Denmark and GALFLU in Galicia, Spain—covering over 466,000 participants aged 65 and above over multiple flu seasons. The primary endpoint was an 8.8% increase in protection against pneumonia or influenza-related hospitalizations versus standard dose vaccines. Secondary endpoints included reductions in cardio-respiratory events, laboratory-confirmed influenza hospitalizations, and all-cause hospitalizations.
Efluelda/Fluzone High-Dose is designed specifically for older adults whose immune systems may be weaker due to age. The vaccine contains four times the antigen level found in standard-dose vaccines.
Sanofi reports that research on its high-dose flu vaccine now spans 15 years and covers more than 45 million older adults worldwide.
Sanofi is a biopharmaceutical company focused on research and development and is listed on EURONEXT: SAN and NASDAQ: SNY.
