The current outbreak of Bundibugyo virus (BDBV) in the Democratic Republic of the Congo highlights the challenges of responding to rare but potentially devastating infectious diseases. Two studies led by researchers from the German Center for Infection Research (DZIF), together with other national and international collaborators, now provide important insights for outbreak response. One study demonstrates how diagnostic tests can be evaluated rapidly during an outbreak; the other investigates the biological properties of the 2026 BDBV strain and whether an existing Ebola vaccine could offer some cross-protection. Both studies were published this month in The Lancet Infectious Diseases.