In a move aimed at improving vaccine stockpiling capabilities, the U.S. FDA has approved a freeze-dried version of Bavarian Nordic’s mpox and smallpox vaccine, Jynneos. The updated formulation offers extended shelf life and easier transportation—key factors for emergency preparedness.

Key Highlights Freeze-dried Jynneos gets FDA nod

• Denmark-based Bavarian Nordic announced U.S. FDA approval of its freeze-dried Jynneos vaccine.

• The formulation offers enhanced transportation and storage advantages over the liquid-frozen version approved in 2019.

Comparable safety and immune response

• Approval was based on clinical data showing that the freeze-dried formulation has immune responses and safety similar to the existing version.

• Freeze-drying removes water to improve product stability and shelf life.

Stockpiling plans underway

• The U.S. Biomedical Advanced Research and Development Authority contracted Bavarian Nordic to develop and supply the freeze-dried Jynneos for national stockpiling.

• Manufacturing began in 2024, and the first deliveries are expected later in 2025.

WHO flags mpox as ongoing emergency

• The World Health Organization noted mpox remains a public health emergency.

• Over 25,000 lab-confirmed cases and 70+ deaths have been reported globally in 2024, with the majority in Congo.

• The U.S. has confirmed 4 cases of the new clade Ib mpox variant as of March 21.

The freeze-dried Jynneos formulation is expected to strengthen the U.S. preparedness strategy for future mpox and smallpox outbreaks. With easier storage and extended shelf life, this version of the vaccine could become critical in responding to global health emergencies and maintaining long-term stockpiles.