The commentary in One Health Outlook explains the journey of the One Health High-Level Expert Panel (OHHLEP) and outputs from the first term. The Quadripartite United Nations Food and Agriculture Organization (FAO), the United Nations Environmental Programme (UNEP), the World Organization for Animal Health (WOAH), and the World Health Organization (WHO) created this panel in 2021 to provide scientific and technical advice on One Health to the Quadripartite.

OHHLEP created several products to lay the foundation for One Health, including an inclusive and expanded definition of One Health, now globally accepted and used. It is also accompanied by foundational principles that ensure One Health actions are effective, fair, equitable and sustainable. In response to the One Health implementation, the Quadripartite developed the One Health Joint Plan of Action, and OHHLEP specifically worked with them to create the theory of change. OHHLEP has continued supporting this plan with an inventory of tools and other implementation products, which will continue into OHHLEP term 2.

The definition and scope of surveillance systems with a One Health focus needed clarification, and we reviewed and compiled examples of current One Health systems and identified optimal key elements of One Health surveillance. It also highlighted the gaps in global and national systems. In response to the Global Pandemic Instrument discussions, we published a whitepaper highlighting the importance of spillover prevention and clarifying this within pandemic prevention, preparedness and response. It provides a definition and the scope of prevention, underlining that this needs to be prioritised and more present in preparedness discussions with a stronger focus on response. It also highlights that the drivers of pathogen spillover need to be addressed following a One Health approach. The outputs of OHHLEP have laid the foundation for the development and implementation of One Health plans by the Member States, as well as the importance of global pandemic agreements.

OHHLEP Term I was instrumental in laying the foundations for the uptake of the One Health approach and also produced several policy opinions that have advanced the structural thinking, guidance, and resources that support the implementation of the One Health approach in countries and kept One Health at the top of the political agenda. The high-level work of OHHLEP Term II will utilise the augmented panel to build on the progress of Term I and maintain the political momentum required to continue progress on implementation. This work continues in Term 2 of OHHLEP, which started in April 2024.