Deadly Nipah Virus Outbreak Has No Vaccine as Doctors Warn of Extreme Lethality

A Nipah virus outbreak in eastern India has prompted renewed warnings from doctors and public health officials, as authorities move to contain confirmed cases and monitor hundreds of people who may have been exposed. The virus, which has no approved vaccine or targeted treatment, is known for its high fatality rate and ability to spread through close contact.

Health officials in West Bengal confirmed several cases in January, including infections among healthcare workers, leading to hospital quarantines and intensified tracing of contacts. While the outbreak remains geographically limited, experts say the situation underlines the risks posed by rare but highly lethal zoonotic diseases.

Medical authorities have stressed that early detection and strict infection control are currently the most effective defences. With symptoms that can resemble more common viral illnesses in the early stages, clinicians have warned that delays in diagnosis can increase the risk of severe outcomes and onward transmission.

What Is the Nipah Virus?

Nipah virus is a zoonotic disease, meaning it can spread from animals to humans. It is most commonly carried by fruit bats and has also been linked to transmission via pigs in some outbreaks. Humans can become infected through contact with infected animals, consumption of contaminated food, or direct person-to-person transmission through bodily fluids.

The World Health Organization has identified Nipah as a priority pathogen because of its epidemic potential and high mortality rate. Previous outbreaks in South and South-East Asia have recorded fatality rates ranging from about 40 per cent to 75 per cent, significantly higher than many other viral infections.

There is currently no approved vaccine or specific antiviral treatment for Nipah virus infection. Medical care is limited to supportive treatment, including intensive care for patients who develop severe respiratory illness or neurological complications.

Symptoms and Transmission Risks

Early symptoms of Nipah virus infection can include fever, headache, muscle pain, sore throat and vomiting. In more serious cases, the illness can progress rapidly to breathing difficulties or inflammation of the brain, known as encephalitis. Patients may experience seizures, coma and, in some cases, long-term neurological damage.

Doctors have warned that the early stages of infection can resemble illnesses such as influenza or Covid-19, which can delay diagnosis. Transmission between people has been documented, particularly in healthcare and caregiving settings where close contact occurs.

Health guidance in affected areas advises people to avoid raw date palm sap and fruit that may have been contaminated by bats, to practise strict hand hygiene, and to seek medical attention promptly if flu-like symptoms develop.

Situation in West Bengal

Indian health authorities confirmed at least five cases of Nipah virus infection in West Bengal in January, prompting the quarantine of around 100 people identified as close contacts. One hospital in Barasat, near Kolkata, has played a central role in the response, with staff placed under monitoring and infection control measures strengthened.

Officials have said the situation remains under close review, with repeated testing being carried out to identify any delayed onset of symptoms. No international spread has been reported.

Public health experts have said the outbreak serves as a reminder of the ongoing threat posed by emerging infectious diseases. With no vaccine available and limited treatment options, vigilance, early detection and strict hygiene practices remain essential to preventing further spread.