Safety and effectiveness of MVA-BN vaccination against mpox in at-risk individuals in Germany (SEMVAc and TEMVAc): a combined prospective and retrospective cohort study
The Lancet Infectious Diseases·
- DOI
- 10.1016/s1473-3099(25)00018-0
- PMID
- 40118087
- PMCID
- —
- OpenAlex
- W4408555862
- Study type
- Cohort study
- Publisher
- Elsevier BV
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The article provides Germany-specific observational evidence on MVA-BN safety and estimated effectiveness in the population studied during the 2022-2023 mpox period. Its findings may inform editorial context about vaccination evidence, including the reported difference in estimated effectiveness by HIV status, but they do not establish causality or confirm a current surveillance pattern.
Structured evidence summary
Research question
The study assessed the safety and reactogenicity of one- and two-dose MVA-BN vaccination and estimated protection against mpox among adults at increased risk in Germany.
Study design
This was a multicentre observational investigation combining a prospective cohort for safety outcomes with an emulated retrospective target trial for effectiveness. The effectiveness analysis compared 3,027 vaccinated participants with 3,027 matched unvaccinated controls.
Population and setting
The prospective cohort included men who have sex with men and transgender adults aged 18 years or older in Germany who reported changing sexual partners, enrolled from July 2022 through December 2023. The effectiveness comparison used vaccinated and unvaccinated participants, with subgroup results reported for people with and without HIV.
Main findings
Among 6,459 prospectively enrolled participants, serious adverse reactions were uncommon; local and systemic reactions occurred more often after dose one than dose two. In the matched effectiveness analysis, 16 mpox cases occurred among vaccinated participants versus 32 among unvaccinated participants, corresponding to an estimated one-dose effectiveness of 57.8% at 14 days or more, with lower estimated effectiveness among people living with HIV. Breakthrough cases had fewer symptoms than cases in unvaccinated participants.
Public-health relevance
The article provides Germany-specific observational evidence on MVA-BN safety and estimated effectiveness in the population studied during the 2022-2023 mpox period. Its findings may inform editorial context about vaccination evidence, including the reported difference in estimated effectiveness by HIV status, but they do not establish causality or confirm a current surveillance pattern.
Important limitations
The evidence comes from observational designs, including an emulated retrospective comparison rather than a randomised controlled trial, so the reported effectiveness estimate should not be treated as a causal vaccine efficacy result. The summary is limited to the supplied single-article abstract and metadata; the original paper is required for decision-grade assessment of confounding, selection, follow-up, subgroup precision, and other study limitations.
GIDS interpretation
For GIDS literature discovery, this article is relevant to mpox vaccination safety and effectiveness in an at-risk population in Germany, with an HIV-status subgroup analysis. It supplies research context only and does not confirm or explain any live surveillance signal.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 12 auditable classifier relationships to diseases, places, topics, and study design.