Understanding MPVX Viral Clearance and Evaluating Transmission Dynamics of MPVX and Mpox Vaccine Effectiveness in Sierra Leone (MOVIE-TRACE SALONE).

A single dose of the MVA-BN vaccine is being tested for its ability to prevent Mpox infection and disease in Sierra Leone, where an outbreak is ongoing. This matters because Mpox is spreading in West Africa, but researchers lack basic data on how long the virus remains in the body, how easily it passes between people, and whether a single vaccine shot offers real protection. Without this information, health officials cannot target interventions to the most vulnerable groups or design effective clinical trials for new treatments. If the research succeeds, it will provide concrete numbers—such as the secondary attack rate within households—that allow public health teams to decide where to deploy limited vaccine supplies. It will also clarify how long infected individuals shed the virus, helping to set isolation guidelines and endpoint criteria for future therapeutic trials. The vaccine effectiveness study could confirm whether a single dose of Jynneos is enough to slow transmission in an outbreak setting, directly informing vaccination strategies across the region.