Orthopoxvirus-specific antibodies wane to undetectable levels one year after MVA-BN vaccination of at-risk individuals

In response to the 2022-2023 mpox outbreak, widespread vaccination with modified vaccinia Ankara-Bavarian Nordic was initiated. Here, we demonstrate that orthopoxvirus-specific binding and MVA-neutralizing antibodies wane to undetectable levels one year post-vaccination in at-risk individuals without pre-existing immunity. Continuous surveillance is essential to understand the impact of declining antibody levels.