New Delhi: Scientists may have found a cure for the Nipah virus, which in May 2018 claimed 17 lives in Kerala. A group reported last week that an experimental drug given to African green monkeys protected them from the virus, which is emerging as a lethal and pandemic disease.
According to the New York Times, the antiviral drug remdesivir protected the monkeys from lethal doses of Nipah virus, for which there is no approved vaccine or cure. Scientists are also testing the drug against the Ebola virus, which has resurfaced in the Democratic Republic of Congo.
An experimental monoclonal antibody is the only available treatment for a Nipah virus infection. It was tested during an outbreak in India last year. The virus gets its name from the first place it was detected in, Kampung Sungai Nipah in Malaysia, in 1998. Fruit bats are the natural hosts of the virus, while pigs are intermediate hosts.
The WHO’s fact sheet on the virus says it can be transmitted to humans from animals (bats, pigs), and can also be transmitted from one human to another. In 2001, a Nipah virus outbreak in West Bengal killed 45 persons. A Nipah virus infection can cause encephalitis and pneumonia and is lethal in about 70% of cases.
In the new trial, scientists gave a lethal dose of Nipah virus to eight African green monkeys. Four of them were given intravenous remdesivir, the experimental drug, and survived. The other four monkeys that did not get the drug died within eight days.
Emmie de Wit, a virologist at the US’s National Institute of Allergy and Infectious Diseases, said the drug “will give us an extra treatment that could be used relatively quickly”, if it wins approval. de Wit is a lead author of the study, which was published in Science Translational Medicine. “The average person who reaches a hospital dies within two days, so it’s hard to protect them once they’re infected,” she told New York Times.
Though Ebola and Nipah belong to different viral families, remdesivir appears effective against both. It has also shown to be effective against two other pandemic threats: Lassa fever and MERS coronavirus, and also against respiratory syncytial virus.
According to de Wit, though the viruses have very different outer shells, their polymerases – the genome-copying enzyme that remdesivir targets –are similar.
The drug was given to the monkeys relatively early after they were exposed to the virus. The authors said the study does not show how effective remdesivir can be if it is administered at a latter time. This is crucial, because disease progression in humans infected with Nipah virus is very rapid, with an average time from disease onset to death of 5 days.
Previous studies have shown that treatment of Nipah virus has to be administered earlier to be efficacious.
“It will be important to determine how long after lethal Nipah virus Bangladesh challenge remdesivir can be administered without losing efficacy,” the authors said.