MVA-BN (‎Modified Vaccinia Ankara – Bavarian Nordic)‎ smallpox and mpox vaccine: interim guidance, 27 November 2024

Overview

The MVA-BN (live Modified Vaccinia Ankara) vaccine is a third-generation smallpox vaccine, which contains a virus that cannot replicate in humans. The virus used in the vaccine is attenuated through multiple passages in non-human cells (i.e. in chicken embryo fibroblast cells) leading to a substantial loss of its virulence while retaining its immunogenic properties. As the MVA-BN vaccine cannot replicate in mammalian cells, it does not produce a lesion at the site of vaccination and has an improved safety profile. This makes it a preferred product in individuals for whom standard replicating vaccine (i.e. ACAM2000) and minimally replicating vaccine (i.e. LC16m8) are contraindicated or not recommended.

Vaccination with MVA-BN is recommended by the WHO Strategic Advisory Group of Experts (SAGE) in the context of an outbreak for persons at high risk of exposure to mpox (including contacts of cases); and in non-outbreak settings for primary preventive vaccination for laboratory personnel working with orthopoxviruses. 1 Recommendations for broader preventive use in non-outbreak setting will require further epidemiologic and vaccination related evidence. The non-replicating MVA-BN vaccine is manufactured by Bavarian Nordic A/S in the same site under the three licensed vaccine brands: Jynneos®, Imvamune® and Imvanex®. 2 WHO SAGE vaccination recommendations apply to all three brands.