Sanofi has announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its two combination vaccine candidates designed to protect against both influenza and COVID-19 in individuals aged 50 and older. This designation aims to expedite the development and review process for these vaccines, addressing the significant health risks posed by these respiratory illnesses, particularly among older adults.
The first vaccine candidate (NCT06695117) combines Sanofi's Fluzone High-Dose, an influenza protein-based trivalent vaccine, with the adjuvanted recombinant Novavax COVID-19 vaccine. The second candidate (NCT06695130) consists of Flublok, an influenza recombinant protein-based trivalent vaccine, also combined with the Novavax COVID-19 vaccine.
Rationale for Combination Vaccines
The development of combination vaccines is driven by the need to simplify immunization programs, offering protection against multiple diseases with fewer injections. A recent meta-analysis indicated that combination booster vaccines could increase COVID-19 vaccine uptake by 56% in individuals aged 50 and above. These vaccines may also reduce administration errors and decrease syringe and vial disposal needs, making them attractive to healthcare professionals.
Clinical Evidence and Tolerability
Both Fluzone High-Dose and Flublok have demonstrated superior efficacy in preventing influenza infections in older adults compared to standard-dose influenza vaccines, as shown in pivotal randomized clinical studies. Real-world evidence further supports their ability to significantly reduce flu-related hospitalizations. The Novavax COVID-19 vaccine has exhibited a better tolerability profile than currently available mRNA COVID-19 vaccines when used as a booster dose and has shown high efficacy against COVID-19 in primary vaccination during Phase 3 trials.
Ongoing Clinical Trials
Sanofi has initiated two separate Phase 1/2 parallel, randomized, modified double-blind, multi-arm studies (NCT06695117 and NCT06695130) to evaluate the safety and immune response induced by the two combination vaccine candidates. These trials aim to provide further insights into the vaccines' performance and potential benefits.
Executive Perspective
Thomas Triomphe, Executive Vice President, Vaccines, at Sanofi, stated, "Building on our immunology expertise and on 12 years of robust clinical and real-world data, we aim to continue leading the way in protection against flu and its severe outcomes. Our goal is to develop a combined flu and COVID-19 vaccine that offers simpler scheduling and fewer injections without compromising on the industry leading levels of efficacy, safety and tolerability of the standalone vaccines included in our combination vaccine."
Impact of Influenza and COVID-19
Influenza remains a significant global health threat, with an estimated 290,000 to 650,000 influenza-related respiratory deaths occurring annually worldwide. In developed countries, most deaths associated with influenza occur in people aged 65 years or older. Adults in this age group also account for most hospitalizations due to influenza, with hospitalization rates twice as high and average hospital stays twice as long compared to younger adults. Furthermore, approximately one-quarter of these patients are readmitted to the hospital within 90 days post-discharge.
COVID-19, caused by the SARS-CoV-2 virus, continues to pose a global health challenge. While most individuals experience mild to moderate respiratory illness, some develop severe complications requiring hospitalization and can result in death. Additionally, many individuals experience long-term sequelae, referred to as "long COVID," with symptoms such as fatigue, cognitive problems, and pain persisting for months or even years after the initial infection. A meta-analysis of 12 studies revealed that 30% of COVID-19 patients have persistent symptoms two years post-infection.
