New Nipah Virus Vaccine Found Safe, Triggers Strong Immune Response: The Lancet

New Delhi: A novel vaccine candidate against the deadly Nipah virus has shown encouraging results in an early-stage clinical trial, raising hopes for effective prevention of the infection in the future. A Phase 1 randomised clinical trial led by researchers in the United States has found that the vaccine, named HeV-sG-V, is safe and capable of generating a robust immune response.

According to the study published in *The Lancet*, all three tested doses and vaccination regimens of HeV-sG-V were well tolerated and successfully induced immune responses in healthy participants. Researchers from Cincinnati Children’s Hospital Medical Center (CCHMC) noted that the rapid development of antibodies within one month of vaccination, along with sustained immunity following two doses, highlights the vaccine’s potential for both outbreak control and preventive use.

First identified in Malaysia in 1999, the Nipah virus continues to cause sporadic outbreaks across South and Southeast Asia, particularly in India. The virus is associated with high fatality rates ranging from 40 to 75 per cent. Due to its severe impact and lack of approved treatments or vaccines, the World Health Organization has classified Nipah virus as a high-priority pathogen, noting mortality rates that can reach as high as 82 per cent.

The findings were described as a “milestone” in Nipah vaccine development by scientists from the Indian Council of Medical Research–National Institute of Virology (ICMR-NIV), Uttar Pradesh, in an accompanying editorial in *The Lancet*.

The Phase 1 trial involved 192 healthy adults aged between 18 and 49 years. While a single dose of the vaccine did not produce sufficient immunity, two doses proved immunogenic. The strongest immune responses were observed in participants who received two doses of 100 micrograms of HeV-sG-V administered 28 days apart. Neutralising antibody levels increased sharply within seven days of the second dose.

Safety outcomes were also reassuring. Mild to moderate pain at the injection site was the most commonly reported side effect. No serious adverse events, hospitalisations, or deaths were recorded during the trial.

In their editorial, ICMR-NIV experts recommended that the vaccine candidate advance to larger Phase 2 trials to further evaluate its safety profile and determine the level of protection it can offer.

Nipah virus disease is an emerging zoonotic infection that can cause acute encephalitis, severe respiratory illness, and frequently death, underscoring the urgent need for effective preventive measures.

— With inputs from IANS