WOAH sets first global rules for African swine fever vaccines

WORLD – The World Organisation for Animal Health (WOAH) has established the first international standards for African swine fever (ASF) vaccines, marking a turning point in global efforts to manage the disease.

The move officially recognizes vaccines as a potential tool for controlling ASF, which has devastated pig populations worldwide.

WOAH standards form the foundation for regulations recognized by the World Trade Organisation, influencing how countries set their import and export policies for animals and animal products.

Following this decision, several nations requested guidance on evaluating ASF vaccines under real-world conditions, prompting WOAH to convene a technical panel in July 2025.

The expert group, which included Dr. Andres Perez and Dr. Rachel Schambow from the University of Minnesota’s Centre for Animal Health and Food Safety, developed a series of field evaluation and monitoring guidelines.

Vaccine type and associated risks

The new documents clarify that current ASF vaccines rely on live attenuated virus strains rather than inactivated ones, meaning vaccinated pigs may shed the virus and potentially experience side effects.

Authorities are therefore urged to weigh the risks of virus shedding and possible adverse reactions against the expected benefits of disease control.

Because ASF symptoms are often non-specific and no serological test exists to distinguish vaccinated animals from infected ones, identifying true ASF cases during vaccine trials remains complex.

The WOAH guidelines also note that evaluating side effects requires carefully designed studies, including pre-defined criteria for what qualifies as a significant reaction.

Field evaluation and surveillance

Governments and pork producers are advised to define their objectives before implementing vaccine programs, whether the aim is to reduce ASF impact or eradicate the virus altogether.

These objectives will determine how field evaluations are designed and assessed.

The framework further calls for continuous monitoring of vaccinated pigs to detect any signs of reversion to virulence or genetic recombination, while also tracking vaccine performance over time.

Transparency in vaccine trials, including open data sharing and collaboration between public and private sectors, is also emphasized.

At the time the guidelines were issued, only Vietnam and the Philippines had begun field use of ASF vaccines, limited to pigs over ten weeks old intended for slaughter.

Both countries, which import most of their pork, have yet to see how international markets will react to the use of ASF vaccines in production systems.

As ASF research progresses, the new WOAH standards and evaluation framework provide an initial roadmap for countries considering vaccine adoption.

Sign up HERE to receive our email newsletters with the latest news and insights from Africa and around the world, and follow us on our WhatsApp channel for updates.