Human trials for Japan-developed Nipah vaccine set to begin in April

A Nipah vaccine developed at the University of Tokyo is set to enter human trials in April, as India reports fresh cases of the deadly virus that currently has no approved treatment

A vaccine candidate against the Nipah virus, one of the world’s deadliest emerging pathogens, is set to enter early-stage human trials in April, offering a potential breakthrough against a disease that currently has no approved treatment or vaccine.

 

According to Nikkei Asia, a Japan-based English-language news magazine, the vaccine has been developed by researchers at the University of Tokyo and will begin Phase 1 clinical trials in Belgium. The development comes at a time of renewed concern, with India confirming two Nipah virus cases in West Bengal earlier this year.

How the University of Tokyo vaccine works

The vaccine candidate developed in Japan uses a recombinant viral vector approach, according to the Nikkei Asia report. Researchers insert a portion of the Nipah virus’s genetic material into a weakened measles virus, a platform already widely used in global immunisation programmes. When the vaccine is administered in humans, antigen proteins similar to those of the Nipah virus are produced. This trains the immune system to recognise and respond to the real virus, potentially preventing illness or reducing disease severity.

 

The report says that animal studies conducted by the University of Tokyo team, including trials in hamsters, demonstrated both safety and protective immune responses.

 

The upcoming Phase 1 trial in Belgium will enrol 60 healthy adult volunteers and will focus on evaluating safety and immune response rather than efficacy. The study is being conducted in collaboration with the European Vaccine Initiative, a Germany-based public–private partnership that supports vaccine development for emerging infectious diseases.

Global efforts to develop a Nipah vaccine

The Japanese candidate is not the only one in development. A separate Nipah vaccine programme involving the University of Oxford entered Phase 2 clinical trials in Bangladesh in December. That study is expected to enrol around 300 participants aged 18 to 55, reflecting growing international momentum to tackle the virus before a larger outbreak occurs.

 

Recognising its epidemic potential, the World Health Organization (WHO) has designated Nipah virus infection as a priority disease under its Research and Development Blueprint.

A virus with a high fatality rate and no cure

Nipah virus is a zoonotic pathogen, meaning it spreads from animals to humans. Fruit bats, particularly from the Pteropodidae family, are its natural reservoir. Humans can become infected through consumption of food contaminated by bat saliva or urine, close contact with infected animals, or through human-to-human transmission via bodily fluids.

 

The WHO estimates the case fatality rate to range between 40 per cent and 75 per cent, depending on the outbreak and access to supportive medical care. Infection commonly presents with fever and headache, and can rapidly progress to respiratory distress or acute encephalitis, which is a dangerous inflammation of the brain.

 

There is currently no licensed antiviral drug or vaccine for Nipah virus. Treatment is limited to intensive supportive care, including respiratory support, fluid management and close neurological monitoring.