Imvanex could soon be authorized in the European Union for children as young as 2 years after a positive opinion from the European Medicines Agency’s (EMA’s) Committee for Medicinal Products for Human Use (CHMP).

At its June 2026 meeting, the committee recommended extending the marketing authorization for Imvanex (live modified vaccinia virus Ankara, Bavarian Nordic A/S) to cover active immunization against smallpox, mpox, and disease caused by vaccinia virus in individuals aged 2 years or older. The vaccine is currently authorized for adults and adolescents aged 12 years or older.

How the Vaccine Works 

Imvanex is a live-attenuated, nonreplicating orthopoxvirus vaccine containing modified vaccinia virus Ankara. Because the virus does not replicate in human cells, it is not expected to cause disease. The immune system recognizes the viral vector as foreign, triggering the production of neutralizing antibodies that cross-protect against all three target orthopoxviruses.

Dosing and Administration 

Imvanex is administered by subcutaneous injection, preferably in the upper arm. Unvaccinated individuals, or those with no prior immunisation against smallpox, mpox, or vaccinia virus, should receive two doses, with the second given at least 28 days after the first. Immunocompromised patients requiring a booster would also follow a two-dose schedule with a minimum 28-day interval.

Smallpox was officially declared eradicated in 1980, with the last known case occurring in 1977, and any use of Imvanex for smallpox protection would be guided by official national public health recommendations. 

Safety and Contraindications

The safety profile of Imvanex is well established from adult data, and the CHMP has assessed it as favorable. The most common adverse reactions are mild to moderate and typically resolve within 7 days.

Clinicians should be aware of the vaccine’s contraindications: Imvanex must not be administered to patients with known hypersensitivity to the active substance or to any trace-level excipients, including chicken protein, benzonase, gentamicin, and ciprofloxacin.

Regulatory Next Steps 

This vaccine was authorized under exceptional circumstances. Comprehensive data on the efficacy and safety of the vaccine under normal conditions of use are not available, reflecting the difficulty of generating complete evidence for these diseases. The company remains required to provide additional data, and the EMA reviews new information annually.

The CHMP opinion will now be forwarded to the European Commission, which will issue the formal marketing authorisation decision. Following that decision, a fully updated summary of product characteristics will be published on the EMA website in all official EU languages. Until then, clinicians should follow current product information and relevant public health guidance.