Authors: A. Bouma, H.A. Lim, T.J.D. van Riet, H.I.J. Roest

Since 2021, high pathogenicity of avian influenza virus H5N1 (HPAI H5N1) has spread worldwide.  It is present in many countries, causing widespread infections in poultry that are often controlled through large-scale culling. The virus is also established in wild bird populations and has led to infections in several mammal species. While human infections remain rare, the risk of a broader public health event, such as a pandemic, cannot be ignored. Reducing virus spread is therefore a priority for both animal and human health. Vaccination could be one of the tools to support this goal and should not be hampered by unjustified trade barriers.

Global situation of HPAI

HPAI H5N1 continues to cause recurring outbreaks in poultry and mammals, with often devastating impacts on the poultry sector and wild animal populations. Control measures rely largely on culling infected flocks, leading to the loss of millions of birds. This approach warrants reconsideration, particularly given the sustained circulation of the virus in wild bird populations. More sustainable, long-term strategies are needed, and vaccination could serve as a valuable additional tool to achieve this goal.

Vaccination, animal health and safe trade

In 2023, the WOAH World Assembly of Delegates adopted Resolution No. 28, recognising vaccination as a complementary disease control tool. WOAH international standards stipulate that vaccination use does not affect a country’s HPAI-free status, provided surveillance demonstrates the absence of infection.

Despite this progress, several challenges remain. Vaccination programmes are currently applied in only a limited number of at-risk countries. Although more countries are considering vaccination, concerns about vaccination and surveillance costs, product value and potential impacts on international trade continue to limit uptake, especially in exporting countries. While some trade barriers are justified, others appear disproportionate and need further discussion.

To address these challenges, the Netherlands set up an international working group on HPAI vaccination and trade. Together with Canada, the European Commission, France, the United Kingdom, the United States of America and WOAH, the Netherlands organised a meeting of this working group last January. Participants agreed to work together to make HPAI vaccination feasible in the near future, providing necessary assurances to allow safe trade.  

Key issues to be addressed

The working group underlined the need to develop and recognise minimum requirements that would facilitate international trade in products from vaccinated poultry and eliminate unjustified trade barriers. The group also noted that agreements with respect to vaccination and trade should be aligned with existing international standards, such as zoning, and should include appropriate surveillance and control measures that support virus control while maintaining trade confidence.

Next steps

A side event will be organised during the WOAH General Session in May. The international working group will present progress to date and outline planned activities. The focus will be on improving understanding of vaccination performance and exploring the development of minimum, widely supported surveillance programme requirements to demonstrate the absence of infection and facilitate trade in products from vaccinated poultry.

In addition, WOAH will develop guidelines for surveillance of HPAI in vaccinated poultry population, with the aim of supporting disease status recognition and safe trade.

Members interested in supporting future vaccination efforts are encouraged to express their interest.

Looking ahead

The goal is to move towards a more sustainable poultry sector that prioritises animal health and welfare, while also protecting public health and the environment.

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WOAH has launched the Guidelines Surveillance of High Pathogenicity Avian Influenza for Smallholder Poultry Systems in Resource-Limited Settings, providing Veterinary Authorities and Veterinary Services involved in high pathogenicity avian influenza(HPAI) surveillance, as well as wildlife, environmental and public health services, animal diagnostic laboratories and other One Health partners with practical recommendations to assist in designing surveillance programmes for the detection of HPAI virus in smallholder poultry systems (SHPS), tailored to the needs and contexts of resource-limited settings.

What the Guidelines Contain

The guidelines Section 1 showcases the diversity and complexity of SHPS beyond the value chain and highlights the importance of community participation to address issues associated with poultry health and enhance effective disease surveillance programmes in such settings.

Section 2 outlines the main objectives, target audience and the international framework, standards and existing tools that link to this guidance.

Section 3 provides six practical phases for developing a surveillance programme in a participative manner — from defining objectives and mapping poultry systems to choosing methods, setting up communication and reporting pathways, and evaluating performance.

Section 4 focuses on training, including a training of trainers model to strengthen local capacity.

The Annex contains ready-to-use tools, templates, figures and evaluation indicators to help users apply the guidance in the field.

Why Did WOAH Develop These Guidelines?

Low- and middle-income countries (LMIC) of the world face several challenges in preventing and responding to avian influenza outbreaks, particularly among smallholder (backyard) poultry farmers. Low-sensitivity surveillance systems in SHPS hinder early detection, thereby increasing the spread of the virus. Furthermore, conventional surveillance programmes often demand substantial and ongoing funding while lacking the flexibility to address the full range of disease surveillance needs in SHPS, particularly where resources are constrained.

In the 90th WOAH General Session in May 2023, following the animal health forum and technical item on avian influenza, Resolution No. 28 was adopted that include the recommendation to support poultry keepers, particularly small holders, in implementing correct usage of disease prevention and control tools, such as enhanced biosecurity, early identification of clinical signs and reporting, to prevent the introduction and spread of HPAI. It was identified as a need to provide Members with practical surveillance guidelines targeting small-scale poultry farmers (backyard), tailored to the local socio-economic context.

To this end, WOAH has published these practical guidelines tailored to local contexts, safeguarding farmers’ livelihoods and ensuring the stability of the poultry industry.

How Were the Guidelines Developed?

In 2025, WOAH launched a consultancy to develop these science-based guidelines. They were authored by experts from the Centre for Applied One Health Research and Policy Advice and Agriculture, Fisheries and Conservation Department, Hong Kong and the Institut National de Recherche pour l’agriculture, l’alimentation et l’environnement, France.

In April 2025, the first draft underwent peer review by a WOAH ad hoc Group, which provided expert opinions and recommendations while ensuring diverse and regional perspectives were considered. The WOAH Scientific Commission for Animal Diseases (SCAD) also reviewed the draft to confirm scientific soundness and alignment with WOAH international standards. Following these reviews and revisions, the guidelines were officially published on the WOAH website (English, French, Spanish) in January 2026.

WOAH encourages users of these guidelines to share their implementation experience and to provide constructive feedback through WOAH Delegates or their representatives, so that this publication can be further refined and adapted to the ever-changing ecology of HPAI viruses, food production systems and surveillance tools.

More information

Recording of the launch webinar on 25 February 2026: Launch of Guidelines on Surveillance of HPAI for Smallholder Poultry Systems in Resource-Limited Settings

Contact: Science and Disease Management Department ([email protected])