The 78th World Health Assembly (WHA) made history by voting to formally adopt the Pandemic Agreement on 20 May 2025 in Geneva, Switzerland, following its approval the previous day1,2. The WHA is the main decision-making body of the World Health Organization (WHO), and every year delegates from the 194 Member States come together to agree on the Organization’s priorities and policies. This announcement follows more than 3 years of intense negotiations, including a 28-hour long discussion to finalize the draft proposal, which outlines approaches for more equitable and effective responses to future pandemics.

The Pandemic Agreement is a direct response to the COVID-19 pandemic and the realization that the structures that were in place to respond to outbreaks were inadequate, particularly when it comes to inequities experienced by lower- and middle-income countries. A key facet of the agreement is to ensure countries collaborate and share resources for a more equitable response to future pandemics1. Given that infectious diseases are not limited by borders, emphasis on global health is essential.

It is encouraging to see that the agreement received overwhelming support with 124 countries voting in favour, no countries voting against and 11 countries abstaining2. However, this meeting is the first WHA without representation from the United States since 1948 (ref. 3). US negotiators were not part of the final discussions and if they do leave the WHO in 2026 as planned, they will not be bound by the agreement. What this means for the future of the agreement and its success is unclear, but its support from other Member States “demonstrated that multilateralism is alive and well, and that in our divided world, nations can still work together to find common ground, and a shared response to shared threats”, as explained by Tedros Adhanom Ghebreyesus, WHO Director-General4. Given the unpredictability of future pandemics, this sentiment presents a much-needed source of cautious optimism about global collaboration, equity and preparedness.

This is only the second time an international agreement like this has been reached. More than 20 years ago, the WHA adopted the first-of-its-kind treaty to tackle the global tobacco epidemic, which entered into force in 2005 (ref. 5). Since then, 180 countries have embraced the treaty, resulting in bans on tobacco advertising and smoking indoors, as well as clear public health warnings, and an estimated 35 million lives saved5. Given the undeniable positive impact it has had on public and global health, the expectation is that a similar treaty could provide a framework for how resources can be shared for pandemic preparedness across borders.

The agreement sets out concrete measures to address this1. It includes strengthening geographically diverse research and development capacities, improving technology and knowledge transfer, and the development of financial mechanisms, global supply chains and logistics networks to enable faster and more effective pandemic responsiveness. Perhaps the most contentious point is the Pathogen Access and Benefit-Sharing (PABS) system, which aims to facilitate efficient exchange of knowledge between pharmaceutical manufacturers and thus enable work on new vaccines, therapeutics and diagnostics more rapidly in a future outbreak1,2,6. This system also proposes that a percentage of pandemic-relevant products are made available to the WHO and supplied at an affordable price, plus sharing of health technologies to enable local production of therapeutics. However, this has raised questions around the scope of transferred knowledge, how benefits would be allocated, and how this could impact research and development, and so discussions will continue over the next year2,6.

Importantly, Article 5 of the agreement specifically refers to a One Health approach to prevent, prepare for and respond to pandemics1. The threat of emerging and re-emerging pathogens is ever-present, especially in the context of increasing urbanization, population growth and a changing human–animal–environment interface. All of these factors increase the risk of spillover from animals to humans, and thus human–human transmission and pandemic potential7. The inclusion of One Health in the Pandemic Agreement, which is a first for an international legal instrument, is a step forwards. Although several points relating to One Health lack specific actions, there is still time for this to be developed before the agreement is ratified and enters into force. The next year of negotiations will be critical to agree and finalize the PABS and hopefully provide more explicit direction for countries to adopt a One Health approach.

The proposed One Health approach underscores the increasingly important need for basic microbiological research that investigates the mechanisms of pathogen evolution, emergence and transmission, which underlie infectious disease outbreaks. Indeed, this issue includes several articles on zoonotic pathogens. An Article by Facciuolo et al. studied humoral immunity in dairy cows infected with highly pathogenic avian influenza H5N1, outbreaks of which have been reported across 17 US states, causing milk production losses. They found that cows develop virus-neutralizing antibodies that limit clinical symptoms such as mastitis, as well as viral shedding on reinfection. These findings indicate that vaccination could be an effective strategy to control infection in cattle and a recent preprint reporting an mRNA vaccine that protected calves from infection supports this8. In another Article, Jo et al. screened wild bats and non-human primates in Brazil and Costa Rica over 14 years to study morbilliviruses in the family Paramyxoviridae, which includes measles virus. They uncovered diverse morbilliviruses in Neotropical bats, which were found to be dominant sources of host shifts, thus improving our understanding of the ecology and evolution of these viruses in wildlife. A Perspective by Yadav et al. focused on another paramyxovirus, Nipah virus, which belongs to the Henipavirus genus and is also transmitted by bats. The authors use Nipah virus as an example of spillover infections to humans and how a One Health approach can be used to prevent future epidemics. They emphasize the importance of clear communication using local languages and community leaders to engage and improve public knowledge, as well as consideration of social, cultural and behavioural factors that can impact viral acquisition and transmission. These works emphasize how zoonotic pathogen research can provide approaches to help predict, prevent and protect against future outbreaks. At Nature Microbiology we aim to provide a platform for rigorous and reproducible data that supports pandemic preparedness endeavours that can feed back into the ongoing discussions on this agreement.