A new experimental vaccine against the deadly Nipah virus has shown promising results in its first human trial, according to a study published in The Lancet. The phase 1 randomised clinical trial found that the vaccine, named HeV-sG-V, was safe and successfully triggered an immune response in healthy adults.
Led by researchers from Cincinnati Children’s Hospital Medical Center (CCHMC) in the United States, the study tested three different doses and vaccination schedules. All regimens were found to be safe and capable of generating antibodies. Researchers noted that while a single dose was insufficient, two doses produced strong and lasting immune responses, particularly when 100 micrograms were administered 28 days apart.
Antibody levels increased significantly within one month of vaccination, with neutralising antibodies rising sharply just seven days after the second dose. This suggests the vaccine could be useful both for outbreak control and preventive use, the researchers said.
The trial involved 192 healthy participants aged 18 to 49 years. The most common side effect was mild to moderate pain at the injection site. Importantly, no serious adverse events, hospitalisations, or deaths were reported.
First identified in Malaysia in 1999, the Nipah virus causes recurrent outbreaks in South and Southeast Asia, particularly in India, and has a mortality rate ranging from 40 to 75 per cent. The World Health Organization classifies Nipah as a high-priority pathogen due to its severe fatality rate and the lack of approved treatments or vaccines.
Scientists from the Indian Council of Medical Research–National Institute of Virology (ICMR-NIV), in an accompanying editorial in The Lancet, described the findings as a milestone in Nipah vaccine development. They emphasized the need for larger phase 2 trials to further assess safety and determine how much protection the vaccine can offer.
Nipah virus disease is a zoonotic infection that can cause acute encephalitis, severe respiratory illness, and death, making vaccine development a critical global health priority.
