The European Commission (EC) has signed a 4-year joint procurement contract with Danish manufacturer Bavarian Nordic to secure up to 8 million doses of the MVA-BN vaccine against mpox and smallpox.

The agreement was concluded on behalf of 20 EU countries. It will enable the purchase of doses for national use as a part of the rescEU stockpile of medical countermeasures to ensure a predictable supply in case of a crisis.

The announcement follows news in October of community transmission of a new mpox variant in Spain, Netherlands, Italy, and Portugal.

The Health Emergency Preparedness and Response Authority (HERA), an EC directorate, regards mpox as a high-priority threat due to “possible emergence of new, more virulent strains, the fact that existing vaccines provide partial cross-protection, and limited availability of effective therapeutic options,” EC spokesperson Eva Hrncirova told MedscapeNews Europe.

Public Health Emergency

Both smallpox and mpox belong to the orthopoxvirus genus. While smallpox was eradicated worldwide in 1980, similarities between the viruses have allowed smallpox vaccines to be repurposed for use against mpox.

Mpox was first declared a public health emergency of international concern (PHEIC) in 2022, following a rapidly transmitted outbreak in the World Health Organization (WHO) European region that then went global. The virus, mpox clade II, was mainly transmitted through sexual contact.

“A combination of changing behavior, infection-control strategies, increase of natural immunity through infections (especially among highly sexually active individuals), and targeted vaccination campaigns led to a sharp decline of the mpox outbreak in 2022,” said Hrncirova.

The PHEIC was lifted in May 2023. However, a second, ongoing PHEIC was put in place in August 2024 after a new upsurge of mpox and the emergence of a new, potentially more dangerous strain called clade Ib in the Democratic Republic of the Congo, which subsequently spread to neighboring countries.

In June 2025, the WHO European Region reported over 200 mpox cases per month. The vast majority were mpox clade II affecting men who have sex with men.

Clade I Transmission

Recent data suggest that the presence of the newer strains, clade Ia and Ib, may be changing in Europe. Of 50 clade I mpox cases in the EU/EEA between August 2024 and November 2025 (mostly clade Ib), 12 did not have a travel link to a country with mpox clade Ib transmission. This finding suggested ongoing local transmission in networks of gay, bisexual, and other men who have sex with men.

These clade Ib cases among men who have sex with men “provide the first evidence of previously undetected circulation of this viral strain in this at-risk population, in which only mpox clade IIb had been reported since 2022,” Olivier Segeral of the University of Geneva, Geneva, Switzerland, told Medscape News Europe.

While men who have sex with men have a moderate risk for mpox clade Ib, risk is low for the EU’s general population, according to the European Centre for Disease Prevention and Control (ECDC).

Healthcare workers likely to care for people with mpox are also at risk, however, as are those who travel to parts of the world with outbreaks, Martin Cormican, consultant microbiologist and professor of bacteriology at the University of Galway, Galway, Ireland, told Medscape News Europe.

People with immunosuppressive diseases require vaccination, he added. “The vaccine is said to be 82% effective in preventing clade II mpox if a person has two doses before they are exposed to mpox. There is less evidence for clade I, but the effectiveness is likely to be similar.” 

Bridging Knowledge Gaps

Uncertainties remain about the transmissibility and clinical severity of clade Ib compared with the clade IIb virus due to the relatively low number of cases so far, according to the ECDC. Among 29 clade Ib cases reported to the agency before the current cases, seven were hospitalized. The agency warned that risk for severe disease may be higher among patients with untreated HIV.

The agency has flagged several knowledge gaps in relation to clade Ib, especially regarding transmission, severity, and the effects of past immunization or infection on long-term protection, said Hrncirova. The Commission has several plans in place to bridge these gaps.

For example, HERA is contributing to the strengthening of the scientific evidence on the immune response provided by the MVA-BN vaccine by supporting a clinical study, Hrncirova said. The study will evaluate and compare the immunogenicity of a booster dose of MVA-BN vaccine given via intradermal or subcutaneous injection. It also will investigate the appropriate timing of the booster dose.

Since 2022, Hrncirova noted, actions like joint procurement agreements for mpox vaccines, donating mpox vaccines to Africa in 2024, and strengthening Africa’s diagnostics and treatment capabilities have helped to build stronger resilience against new outbreaks in the EU.

Hrncirova, Cormican, and Segeral reported no relevant financial relationships.

Annie Lennon is a medical journalist. Her writing appears on Medscape, WebMD, and Medical News Today, among other outlets.