US FDA approves freeze-dried version of Bavarian Nordic's mpox, smallpox vaccine
March 31, 2025
The U.S. FDA has approved a freeze-dried version of Bavarian Nordic’s Jynneos vaccine for mpox and smallpox, a key development for long-term emergency preparedness. Unlike the liquid-frozen formulation approved in 2019, the freeze-dried version offers improved shelf life and easier storage and transportation, ideal for global stockpiling. Developed under a U.S. BARDA contract, deliveries will begin in late 2025. This milestone comes as WHO continues to classify mpox as a public health emergency, with over 25,000 confirmed cases globally in 2024, including four U.S. cases of the more transmissible clade Ib. Broader vaccine access and storage stability are now critical.
Bavarian Nordic has received FDA approval for a freeze-dried formulation of its Jynneos vaccine for mpox and smallpox, a timely advancement in global health preparedness. The new formulation offers significant benefits over the liquid-frozen version previously approved in 2019, including improved transportation, storage conditions, and shelf life—key factors for national and international vaccine stockpiling. The approval was based on clinical trial data showing comparable safety and immune response profiles between the two formulations.
The freeze-dried vaccine was developed under a contract with the U.S. Biomedical Advanced Research and Development Authority (BARDA), with manufacturing launched in 2024. The first deliveries are expected in late 2025 and will be used to bolster strategic national stockpiles. This logistical enhancement arrives as the global mpox situation remains volatile. In February 2025, the World Health Organization reaffirmed mpox as a public health emergency of international concern, with more than 25,000 laboratory-confirmed cases and over 70 deaths reported globally this year—most of them in the Democratic Republic of the Congo.
Additionally, the emergence of clade Ib mpox, a more transmissible variant, has been detected in 18 countries, including four confirmed cases in the United States as of March 21. As global transmission continues and new strains emerge, efficient and scalable vaccination strategies are essential.
The FDA’s approval of a more durable and easily deployable vaccine formulation represents a crucial step toward enhancing readiness for both endemic and emerging mpox threats. With continued case growth and the spread of clade Ib, health agencies must focus not only on increasing vaccine availability but also on ensuring its rapid and sustained deployment in at-risk populations. The freeze-dried Jynneos vaccine is a key asset in that effort.