There is no vaccine yet for the deadly virus. Nipah was first identified about 25 years ago in Malaysia and has led to outbreaks in Bangladesh, India and Singapore.
The first participants in the Oxford trial received doses of the vaccine over the last week. The shot is based on the same technology as the one used in AstraZeneca and Serum Institute of India's COVID-19 shots.
The 51-patient early-stage trial will take place in Oxford and will examine the safety and immune response of the vaccine in people aged 18 to 55 years, a spokesperson for the University's Pandemic Sciences Institute said.
Further trials are expected to follow in a Nipah-affected country.
"Nipah has epidemic potential, with its fruit bat hosts found in areas home to over two billion people. This trial is a step forward in efforts to build a suite of tools to protect against this killer virus," said Dr In-Kyu Yoon, an executive at the Coalition for Epidemic Preparedness Innovations (CEPI).
The trial is led by Oxford Vaccine Group and funded by CEPI, a global coalition that supports the development of vaccines against emerging infectious diseases.
Moderna in 2022 also started an early-stage clinical trial of a Nipah virus vaccine, which it co-developed with the U.S.' National Institute of Allergy and Infectious Diseases.
In September, India's Kerala state witnessed its fourth Nipah outbreak in five years, with six people infected and two deaths.
The infection can cause fever, headache, cough and difficulty breathing, with brain swelling likely to follow. Its fatality rate is estimated at 40% to 75%, according to the World Health Organization.
