Sanofi has announced positive data from the first study of their high-dose influenza vaccine with a COVID-19 messenger RNA (mRNA) booster shot. Interim results from the first co-administration descriptive study of Sanofi’s Fluzone® High-Dose Quadrivalent vaccine with Moderna’s COVID-19 mRNA investigational booster dose show that the administration of the vaccines at the same visit had similar immunogenicity responses and a similar safety and tolerability profile compared to each vaccine administered individually.

Fluzone® High-Dose Quadrivalent is a high-dose quadrivalent influenza vaccine, indicated for adults aged 65 and older in the United States and Canada. It is also licensed under the brand name Efluelda® in Europe where it is indicated for adults aged 60 and older. According to Sanofi, Fluzone High-Dose is the only influenza vaccine that has demonstrated reductions in influenza-related complications such as hospitalisations due to cardiovascular events and pneumonia, over 10 consecutive seasons in more than 34 million people aged 65 and older.

This descriptive study is being conducted in the US and is currently following participants for six months for safety. It includes around 300 participants aged 65 years of age and older who received two doses of a COVID-19 mRNA vaccine as primary vaccination at least five months prior to enrolment. The study assesses the safety profile and immune response when COVID-19 mRNA investigational booster vaccine (100mcg dose) and high-dose quadrivalent influenza vaccine are administered simultaneously. Full results of the study will be published later this year.

“This season, more than ever, it is critical to help protect the older adults, who are at especially high risk for both severe COVID-19 and complications from influenza, which can include heart attacks and strokes,” stated Dr Michael Greenberg at Sanofi. “This is the first study to provide supportive evidence for vaccinating against influenza at the same time as a COVID-19 mRNA booster in seniors. These positive results could facilitate the implementation of Northern Hemisphere influenza and COVID-19 booster vaccination campaigns, especially in this high-risk population.”