African swine fever: WOAH vaccine standard adopted 

African swine fever (ASF) is one of the most devastating diseases for domestic pigs and wild boars worldwide. The highly contagious, haemorrhagic disease can have a mortality rate as high as 100%, making its spread a concern for animal health, local economies, farmers livelihoods, and biodiversity.  

Since January 2022, at least 12 countries have reported a first occurrence of ASF and at least 11 countries have reported its spread to previously unaffected zones. Between January 2022 and 28 February 2025, ASF led to over 2 million animal losses worldwide, with Asia and Europe being most affected. Losses of this scale can be devastating. Pigs, often raised on family-run pig farms, are the primary source of household income in many countries. More than that, ASF, if uncontrolled, could throw food security into jeopardy as pork meat accounts for 31% of the global protein intake.

Though affected countries have and continue to implement measures to halt the spread of the disease, controlling ASF has been historically difficult due to a lack of vaccines or effective treatment. In recent years, however, the research community has made large strides in producing ASF vaccines — some of which have received approval for field use in a small number of countries.

A new vaccine standard  

The World Organisation for Animal Health (WOAH) encourages innovation in vaccine development; however, it remains imperative that the vaccines used in the field are of high-quality and have been proven safe and effective. Using poor quality or non-compliant vaccines could threaten ASF control measures as they may not provide protection against the disease. In fact, ineffective vaccines could result in the spread of the disease or in vaccine viruses recombining with the circulating ASF virus, creating new strains that could potentially spread more easily and escape detection. 

This year, at WOAH’s 92nd General Session, an ASF vaccine standard was adopted to demonstrate our Members’ commitment to tackling the disease and to use safe, compliant vaccines. This standard aims to provide Members and manufacturers with minimum standards for safe and effective vaccines. It highlights the need for vaccines to be effective in reducing the severity of the disease, limiting transmission of the virus and providing immunity to the animal, therefore reducing production losses due to ASF. They must be proven safe before use, meaning they do not cause lasting or severe clinical signs, harm the environment or contain wild ASF viruses or other harmful agents. Finally, they must match the circulating ASF genotype in the region of vaccination to ensure effectiveness and limit the risk of two different strains combining to form a new, harder to manage strain.  

Multi-layered ASF control 

Vaccination is a powerful tool if vaccines are made in accordance with WOAH international standards. However, improvements in vaccine development and strengthened international standards for vaccine approval do not position vaccination on its own as a viable method for ASF control.

Successful disease management involves a combination of biosecurity practices, import measures and animal movement control to which vaccines are a complementary action. The decision to vaccinate against ASF should fall on the Veterinary Authority and take into account the local epidemiology of the disease and the financial and human resources available for vaccination operations and post-vaccination surveillance. 

With continued investment in research, ASF control is within reach. High quality, effective vaccines paired with existing disease control measures could substantially lower the negative impact of ASF on animal health and human livelihoods.