Scientists make breakthrough in developing Nipah virus vaccine for pigs

Scientists at The Pirbright Institute have taken a major step forward in tackling one of the world's most dangerous viruses, the Nipah virus, by evaluating vaccine candidates for pigs.

The Nipah virus is zoonotic, meaning it can be transmitted from animals to humans. Originating in Old World fruit bats, the virus primarily affects pigs and humans.

The virus was first identified during a major outbreak in 1998-99 in Malaysia which led to the culling of nearly half the country's pig population and resulted in significant economic losses.

Since then, the virus has continued to cause outbreaks in South and Southeast Asia, particularly in Bangladesh and India, where human-to-human transmission and consumption of contaminated food, such as date palm sap, have led to high fatality rates.

Infected people can develop encephalitis (swelling of the brain) as well as respiratory problems. The disease often begins with flu-like symptoms but can rapidly progress to coma and death. Currently, there are no licensed vaccines or treatment for use in pigs or humans, yet the disease poses a major threat to public and animal health.

Nipah is designated a priority disease by the World Health Organization (WHO) and a priority pathogen by the UK Health Security Agency, meaning research and development is urgently needed.

Now, a team of researchers from the UK, Australia and Bangladesh, led by scientists at The Pirbright Institute, have tested experimental Nipah vaccines in pigs, aiming to cut off the virus at one of its key transmission routes.

Published in npj Vaccines, the study describes the development of three vaccine candidates using different viral surface proteins. One of the candidates used the same viral vector platform as the Oxford/AstraZeneca COVID-19 vaccine.

The team assessed the immunogenicity - the vaccine's ability to trigger an immune response - in mice and pigs, as well as it's potential to protect pigs against Nipah. They then carried out further trials in 'backyard' pigs under field conditions in the 'Nipah belt' region of Bangladesh.

All three vaccines successfully protected pigs from infection. Despite differences in the strength of the immune response, all candidates performed well, showing immunity in pigs vaccinated under field conditions in the Nipah-endemic regions.

By preventing Nipah outbreaks in pig populations, we can in turn mitigate human infections, protect economies, public health and food security. Our research moves us one major step closer to achieving this goal."

Professor Simon Graham, Group Leader of the Porcine Reproductive and Respiratory Syndrome (PRRS) Immunology group, The Pirbright Institute

The team is now working with partners in Germany to develop a cost-effective dual vaccine that could protect pigs against both Nipah and a common swine disease, combining pandemic preparedness with practical benefits for farmers.

As scientists race to stay ahead of high-threat emerging diseases, this work underscores the importance of a 'One Health' approach where the health of animals, people and ecosystems is tackled together, not in isolation.