Sanofi is shifting its focus away from developing an mRNA-based flu vaccine, even as the company’s leadership continues to express confidence in its broader vaccine business.
A Sanofi spokesperson stated to Fierce Biotech, “Sanofi has deprioritized its mRNA-based seasonal flu vaccine program and does not anticipate launching an mRNA-based seasonal flu product in the near term.” The company disclosed in its 2025 annual report that it had discontinued a Phase I asset within this portfolio.
The experimental vaccine, known as SP0237, was designed as a hexavalent mRNA shot for seasonal influenza. According to Sanofi’s July 2025 pipeline update, SP0237 was undergoing a Phase I/II trial focused on safety and immune response in adults aged 50 and older. The federal clinical trials database indicates the study remains active but is no longer recruiting participants, with completion targeted for April this year. It remains uncertain whether Sanofi will publish results from the trial.
Despite scaling back its efforts on the mRNA flu vaccine, Sanofi maintains that it is still committed to using mRNA technology as part of its overall vaccine development approach. The spokesperson added that the company “remains fully committed to mRNA technology as a key part of our multi-platform vaccine development strategy.”
During a press call Thursday morning, CEO Paul Hudson reiterated his belief in vaccines’ importance despite declining sales and skepticism in the United States. Hudson said vaccines are “the number one gift to public health,” adding, “It doesn’t change just because of the debates that are happening.”
Since taking office at the Department of Health and Human Services, Secretary Robert F. Kennedy, Jr. has implemented policies that have reduced access to vaccines for many Americans. In May 2025, he removed COVID-19 vaccines from standard immunization guidelines for healthy pregnant women and children. He also replaced members of the CDC’s vaccines advisory panel with individuals who have expressed skepticism or conflicts regarding vaccination.
Kennedy has publicly questioned both the effectiveness and safety of vaccines, which has contributed to increased public doubt about immunization.
These developments have affected revenues across much of the vaccine industry. Sanofi reported a 2.5% decrease in year-over-year vaccine sales with lower earnings seen throughout most products including those targeting respiratory syncytial virus (Beyfortus), polio, pertussis, and hemophilus influenza.
Kennedy has also targeted funding for mRNA research specifically related to upper respiratory diseases. In August he withdrew support from 22 research contracts involving mRNA—including one from Sanofi—though later clarified that funding would continue for projects using mRNA technology against cancer.
