University of Tokyo–led research enters a crucial phase as a potential vaccine against one of the world’s deadliest viruses is tested in humans for the first time.

Japanese researchers have taken a major leap in the global fight against emerging infectious diseases by launching the world’s first human clinical trials for a Nipah virus vaccine.

Scientists at the University of Tokyo confirmed that a leading vaccine candidate has advanced into human testing, a landmark development in efforts to curb a virus known for its devastating fatality rate. The trials are scheduled to begin in Belgium this April, reflecting growing international cooperation in pandemic preparedness.

The Nipah virus is among the most lethal zoonotic pathogens, causing severe respiratory complications and acute brain inflammation. With a mortality rate that can soar to 75 percent, the virus poses a serious threat to global health, particularly in regions where outbreaks recur. Until now, no approved vaccines or targeted treatments have existed.

Researchers say the trial is not only a scientific breakthrough but also a strategic move to prevent future pandemics. As diseases increasingly jump from animals to humans, early intervention tools like vaccines are critical for rapid response and containment.

If successful, the vaccine could equip health authorities with a long-awaited defense against Nipah, potentially saving thousands of lives and strengthening global readiness against emerging viral threats.