Sanofi's Chlamydia Vaccine Granted FDA Fast Track Designation

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The US FDA has granted fast track designation to Sanofi’s mRNA vaccine candidate for the prevention of chlamydia infection. The designation aims to expedite the development and review of the vaccine due to its potential to address a serious health condition and an unmet public health need, according to Sanofi.

The vaccine candidate is designed to protect against primary genital tract infection and reinfection caused by Chlamydia trachomatis. Following a promising preclinical program, Sanofi is set to initiate a phase 1/2 randomized clinical study to evaluate the immunogenicity and safety of the vaccine in adults aged 18 to 29 years. The trial is expected to commence in the coming days.

“Millions of people currently live with undiagnosed chlamydia, including asymptomatic infection that can also cause severe long-term health effects if left untreated,” Jean-François Toussaint, global head of vaccines R&D, Sanofi, said today in a press release. “Antibiotics to treat chlamydia have not been successful in controlling rising infection rates. With our program we aim to make chlamydia a preventable disease through vaccination.”

Chlamydia is a common bacterial infection of the reproductive tract that can contribute to pelvic inflammatory disease in women, increasing the risk of pregnancy complications and infertility. In 2020, an estimated 129 million cases of chlamydia were reported worldwide among adults aged 15 to 49 years, with the highest infection rates observed in adolescents and young adults. Although chlamydia can be treated with antibiotics, over 80% of cases are asymptomatic, leading to undetected infections and unintentional transmission.

Efforts to control chlamydia infection rates through public health programs have proven insufficient, underscoring the need for an effective vaccine. Sanofi’s vaccine development is part of the Translational Science Hub, a collaboration with the Queensland Government, Griffith University, and the University of Queensland, connecting researchers in Australia with Sanofi scientists in France and the US.

The phase 1/2 clinical study will be a critical step in determining the vaccine’s potential role in preventing chlamydia infections and reducing associated health complications, according to the press release.

Source: Chlamydia vaccine candidate granted fast track designation by the US FDA. News release. Sanofi. March 26, 2025. Accessed March 26, 2025. https://www.news.sanofi.us/2025-03-26-Chlamydia-vaccine-candidate-granted-fast-track-designation-by-the-US-FDA