Introduction: Nipah virus is an emerging pathogen in the Paramyxoviridae family, which appers today a real threat for eventual pandemy. Upon transmission of Nipah virus from its natural reservoir, the fruit bats, to humans, it causes respiratory and neurological disease with a case-fatality rate about 70%. Human-to-human transmission has been observed during Nipah virus outbreaks in Bangladesh and India.
Nipah virus is a zoonotic envelop virus which was first identified during an outbreak in Malaysia in 1998 and caused deadly outbreaks in South- and Southeast Asia, particularly in India and Bangladesh.
Fig. 1. Electronc Microscopic photo of Nipah virus particle.
Credit: National Institute of Allergy and Infectious Diseases
The 2026 Nipah Virus Outbreak in India: India has reported a total of 5 cases of Nipah Virus infection all from West Bengal, earlier January 2026. (1)
It is reported that, all the 5 infected patients are healthcare workers. India is facing against a serious public health challenge as authorities work to contain a fresh outbreak of the deadly Nipah virus. In January 2026, health officials confirmed multiple cases in West Bengal, triggering emergency containment measures, home quarantines, and elevated disease surveillance across several states. With no approved vaccine or specific antiviral treatment available, the outbreak has raised a global concern over the virus’s epidemic potential. (2) Furthermore, nearly 100 people identified as close contacts, therefore instructed to quarantine at home. Patients who tested positive were moved into intensive care isolation units, with officials confirming that at least one patient remains in critical condition.
As Nipah virus is considered one of the world’s most dangerous zoonotic pathogens due to its high fatality rate and ability to spread from animals to humans and between people, the WHO/World Health Organisation has classified it as a priority disease.
Remdesivir as a hope for this viral infection:
Veklury™ (Gilead Sciences): Sulfobutylether-betadex enabled Remdesivir (source: Wikipedia)
In a study published in 2019, researchers reported on the efficacy of remdesivir (Gilead Sciences), a broad-spectrum antiviral nucleotide prodrug, against Nipah virus Bangladesh genotype in African green monkeys. (3)
Animals were inoculated with a lethal dose of Nipah virus, and a once-daily intravenous remdesivir treatment was initiated 24 hours later and continued for 12 days. Mild respiratory signs were observed in two of four treated animals, whereas all control animals developed severe respiratory disease signs. In contrast to control animals, which all died to the infection, all remsdesivir-treated animals survived the lethal challenge, indicating that remdesivir represents a promising antiviral treatment for Nipah virus infection. One group of animals received remdesivir (10 mg/kg) in vehicle solution (12% sulfobutylether-b-cyclodextrin in water adjusted to pH 3.5 with hydrochloric acid), whereas the other group received the same vehicle without remdesivir.
Results: Two groups of four African green monkeys were infected intranasally and intratracheally with a lethal dose of Nipah virus Bangladesh. After 24 hours incubation time, one group of animals was treated intravenously with remdesivir, and the other group was administered with vehicle alone (12% solution of sulfobutylether-beta-cyclodextrin). All vehicle-treated animals developed disease signs including mild respiratory signs starting about 3 to 4 days post-inoculation, this disease rapidly progressed to respiratory distress after 7 and 8 days, and died.
The clinical scores in the remdesivir-treated animals have all returned to baseline by 21 days after infection, and all animals survived without further clinical signs until the end of the experiment on 92 days post-infection.
Summary:
- The above study demonstrated that none of the remdesivir-treated animals developed severe respiratory disease, and all survived the acute lethal Nipah virus Bangladesh challenge.
- Since no therapeutics with proven efficacy are currently available to fight Nipah virus disease in humans, it seems worthwile revisiting sulfobutylether-enabled remdesivir.
References:
1.Region on watch as India declares Nipah virus outbreak contained | Health News | Al Jazeera
2. Deadly Nipah returns to Bengal after 19 years as mystery surrounds source of infection – India Today
3.Michael K. Lo et al. Remdesivir (GS-5734) protects African green monkeys from Nipah virus challenge, Sci. Transl. Med. 11, eaau9242 (2019) 29 May 2019. Doi: 10.1126/scitranslmed.aau9242
4. C. E. Mire, et al. Pathogenic differences between Nipah virus Bangladesh and Malaysia strains in primates: Implications for antibody therapy. Sci. Rep. 6, 30916 (2016). https://doi.org/10.1038/srep30916
5. T. K. Warren, et al. Therapeutic efficacy of the small molecule GS-5734 against Ebola virus in rhesus monkeys. Nature 531, 381–385 (2016). https://doi.org/10.1038/nature17180