The case for investing in One Health

One Health is an integrated approach designed to balance and optimise the health of people, animals, plants and ecosystems. This approach is essential for addressing interconnected global challenges such as climate change, biodiversity loss, pollution and antimicrobial resistance (AMR). The cost of health threats is significant; for example, the International Monetary Fund estimated the cumulative output loss from the COVID-19 pandemic to be USD 13.8 trillion between 2022 and 2024. Additionally, AMR is projected to cause a potential loss of 3.8 per cent of global annual gross domestic product by 2050. Other costs include USD 95 billion annually in human productivity losses from unsafe food and over USD 290 billion in losses from plant diseases and invasive insects.

Investing in One Health-centred pandemic prevention is estimated to cost between USD 10.3 billion and USD 11.5 billion per year. This figure represents less than 1 per cent of the response costs for the COVID-19 pandemic in a single year. Proactive measures, such as enhancing veterinary services, improving on-farm biosecurity and reducing deforestation, are far more cost-effective than reactive, siloed responses.

Barriers and opportunities for investing in One Health

Several barriers hinder holistic financing for One Health. These include sectoral budgeting and reporting structures that do not incentivise cross-sectoral coordination, as well as high initial transaction costs for establishing new governance mechanisms. The complexity of evaluating One Health effectiveness can also discourage investors. However, opportunities exist to strengthen investment through enhanced evidence, the use of collaborative governance mechanisms and the recognition of public goods and positive externalities. Win-win scenarios that reward multisector collaboration can create positive incentives by demonstrating measurable value addition for all participating sectors.

Evidence on the financial and economic value of One Health

A systematic literature review of 97 studies found that 80 per cent reported a positive economic value or return on One Health initiatives. Most research to date has focused on only two sectors, typically human and animal health. Evidence from case studies demonstrates substantial returns. In Liberia, a One Health economic model for protected areas estimated a 10-year net present value of USD 21.6 billion. In Egypt, a public-private partnership enabling farmers to compost poultry carcasses increased annual profits by 1.4 per cent, translating to USD 45.9 million at scale. In Indonesia, a programme for rabies management generated a benefit-cost ratio of USD 6.56 to 14.35 for every USD 1 invested, averting between 65.3 and 142.8 Disability Adjusted Life Years.

Attracting more funding and financing for One Health

Securing investment requires a multistakeholder endeavour involving national governments, multilateral development banks and private sector actors. International aid is currently being reduced, placing additional pressure on low- and middle-income countries to tap domestic resources and leverage mechanisms like the Pandemic Fund. There is a critical need for rigorous economic analysis and monitoring to demonstrate value for money and secure long-term, scalable financing. Advocacy anchored in solid evidence is essential for maintaining political commitment, as seen in G7 and G20 declarations.

Making investment decisions

To support informed decision-making, research must expand to include a broader range of One Health topics and better investigate how the 4Cs (communication, coordination, collaboration and capacity building) add value compared to isolated working. Addressing the distribution of costs and benefits across sectors is also vital. For instance, while agricultural services may bear the cost of rabies vaccinations, the public health sector reaps the benefits of reduced human infections. Advancing methods to value non-monetary benefits, such as social well-being and environmental protection, will provide a more comprehensive picture of the approach’s impact.

Where additional evidence is needed

Global-scale studies are often too abstract for local policymakers. There is a need for smaller-scale, context-specific research that can be scaled up if successful. Gaps remain in understanding how deep integration in the policy cycle adds value beyond traditional sectoral methods. Furthermore, more studies are needed to examine the integrated monetary and non-monetary effects across more than two sectors.

Filling knowledge gaps and opportunities for leveraging greater One Health investments

Future actions to justify investment include analysing current contexts to capture relevant costs across sectors and recognising that benefits often accrue over the medium to long term. Mapping the distribution of costs and benefits among stakeholders can help identify inequitable allocations that might reduce overall efficiency. Engaging stakeholders throughout the process ensures that assumptions are validated and priorities are refined for actionable investment insights.

Main takeaways

One Health maximises co-benefits across health domains while minimising unintended negative consequences. While recent crises have underscored the urgency of this approach, investment remains limited due to challenges in demonstrating financial returns. Key strategies for scaling impact include expanding research, recognising public goods, addressing cost-benefit distribution and utilising pooled or blended funding mechanisms supported by sustained advocacy and institutionalised coordination.