Bavarian Nordic wins FDA nod for freeze-dried mpox, smallpox vaccine

USA – The U.S. Food and Drug Administration (FDA) has granted approval to Bavarian Nordic’s freeze-dried version of the Jynneos vaccine for mpox and smallpox.

The new formulation offers improved stability and longer shelf life, enhancing preparedness for potential outbreaks and bioterrorism threats.

The approval, announced on April 1, 2025, comes as part of Bavarian Nordic’s broader efforts to expand the availability and utility of Jynneos, particularly in emergency stockpiles.

The newly approved formulation maintains the same immunogenicity and safety profile as the previously approved liquid-frozen version, but with the added advantage of being easier to store and transport.

Improved stability and supply chain resilience

The freeze-dried formulation of Jynneos is expected to enhance the resilience of public health infrastructure.

Its longer shelf life compared to the liquid-frozen version reduces logistical challenges associated with vaccine distribution and storage, particularly in regions with limited cold-chain capabilities.

Approval was supported by a Phase II trial involving 651 healthy volunteers who received two doses of either the liquid-frozen vaccine or the freeze-dried counterpart.

The study found no statistical differences in immune responses between the groups and reported no serious adverse events, although the freeze-dried group exhibited slightly higher local reactions.

Bavarian Nordic also provided non-clinical and manufacturing data to the FDA as part of the supplemental biologics license application (sBLA) submitted in May 2024.

Bavarian Nordic’s President and CEO, Paul Chaplin, highlighted the importance of the approval, stating, “Today’s FDA approval represents a significant milestone in our development of this next generation of Jynneos and in our collaborative efforts with the US Government to strengthen public health security.”

Ongoing collaboration with the us government

The US Government has been working closely with Bavarian Nordic to ensure a stockpile of the vaccines is available in the event of a mpox outbreak.

The country has been stockpiling since 2010 and intensified efforts following the 2022-2023 outbreak, where mpox spread to all 50 states.

Bavarian Nordic is collaborating with the US Biomedical Advanced Research and Development Authority (BARDA) to replenish the vaccine stockpile.

In 2017, BARDA awarded Bavarian Nordic a contract to develop a freeze-dried version of the vaccine with a longer shelf-life to replace the stockpile.

This initiative was further strengthened by a follow-up US $156.8 million contract in 2024 to support these efforts.

Manufacturing of the freeze-dried version began in 2024, and the first vaccines are expected to be delivered later in 2025.

Market implications and global reach

The FDA’s approval arrives as public health officials remain vigilant against potential outbreaks of mpox, which resurfaced globally in 2022.

While Jynneos was initially the only FDA-approved vaccine for mpox prevention, Emergent BioSolutions’ ACAM2000 became the second vaccine approved for high-risk individuals in August 2024.

Bavarian Nordic’s product, also known as MVA-BN and Imvanex in other regions, has been instrumental in combating the ongoing mpox outbreak in Africa.

The biotech has supplied over a million doses of the vaccine to affected countries and pledged to ramp up production further.

The World Health Organization (WHO) continues to classify the mpox outbreak as a public health emergency, with over 100,000 cases globally in the ongoing outbreak of Clade II mpox.

Four cases of Clade I mpox have been reported in the US, with the most recent occurring in New Hampshire and New York in February 2025.