A risk-gate mechanistic–ecological framework for assessing emergence potential of henipa-related viruses

Henipa-related viruses can cause severe disease following rare zoonotic introductions, yet spillover alone does not determine the likelihood of outbreak emergence. Here we propose a risk-gate mechanistic-ecological framework to assess emergence potential across henipa-related viruses. Using the well-characterized henipaviruses Nipah and Hendra together with the more recently described Langya and Mojiang viruses as comparative examples, we define a sequential pathway linking upstream exposure (Step 0) to host entry and tissue access (Gate 1), within-host replication and immune antagonism (Gate 2), and transmission amplification (Gate 3). By tagging the strength of available evidence and identifying gate-specific knowledge gaps, the framework distinguishes biological constraints from operational uncertainties including diagnostics, infection prevention and control (IPC), and response capacity. This evidence-tagged framework provides a practical One Health roadmap for comparing established and emerging henipa-related viral threats. We present it as a conceptual, review-oriented tool rather than a validated predictive model and outline how future retrospective outbreak analyses could test its utility.