Speaker
Description
Background: Real-world evidence on the clinical presentation and severity of mpox infections following vaccination with the MVA-BN vaccine remains limited.
Methods: We conducted a scoping review and meta-analysis of 45 studies published between 2022 and 2025 to epidemiologically characterise mpox breakthrough infections following MVA-BN vaccination.
Results: 17 studies provided suitably stratified data for an odds ratio estimation of progression to more severe forms of disease, conditional on first being recognised as a case. Vaccinated cases had significantly lower odds of developing systemic symptoms and becoming hospitalised compared to unvaccinated cases.
Interpretation: Although many breakthrough infections after MVA-BN vaccination have been documented, the vaccine effectiveness (VE) in reducing the rate of infection is unknown. We did not estimate total VE= 1-(1-VE_S)*(1-VE_P), with VE_S the VE in reducing the risk of becoming a case and VE_P the VE in reducing the risk of progression to severe outcomes once already diagnosed. The 17 studies contributed to an estimate of VE_P but not to an estimate of VE_S, which could be the primary benefit of the vaccine in protecting against severe mpox disease. Future studies are needed to address this.
