London: An international team of researchers have found the Covishield-like vaccine successful in monkey trials against the Nipah virus, suggesting this vaccine may help us fight the lethal Nipah infection.
Researchers from the University of Oxford, and the US National Institutes of Health investigated the efficacy of ChAdOx1 NiV in the eight African green monkeys and published the results on the pre-print server bioRxiv.
ChAdOx1 NiV is based on the same vector as ChAdOx1 nCoV-19, which has been approved for emergency use in over 60 countries worldwide and administered to 100 million people.
"In both hamster and monkey NiV models, vaccination with ChAdOx1 NiV resulted in induction of high antibody titers coupled with complete protection against lethal NiV disease," said Vincent J Munster, Laboratory of Virology, National Institute of Allergy and Infectious Diseases, NIH.
While one group of four monkeys were administered either two shots or a single shot of the ChadOx1NiV, the other group were injected with dummy protein (ChAdOx1 GFP), again vectored by ChAdOx1.
All the eight were then or artificially infected with the real Nipah virus, some given via the nose and others through the throat. When artificially infected with the real Nipah virus, the control animals displayed a variety of signs and had to be euthanised between five- and seven days post-inoculation.
"In contrast, vaccinated animals showed no signs of disease, and we were unable to detect infectious virus in all but one swab and all tissues," the researchers said.
"No to limited antibodies against fusion protein or nucleoprotein IgG could be detected 42 days post-infection with real NiV, suggesting that vaccination induced a very robust protective immune response preventing extensive virus replication," said Sarah C Gilbert, from the Jenner Institute Nuffield Department of Medicine at Oxford.
The researchers had previously shown that a single dose of ChAdOx1 NiV provides full protection in hamsters. The team also found very limited evidence of virus replication in vaccinated animals, all but one swab was negative for infectious virus and no virus was found in tissues obtained from vaccinated animals.
These data suggest the vaccine may provide close to complete protective immunity in the monkeys, the researchers explained.
Safety profiles obtained in ChAdOx1 nCoV-19 clinical studies combined with efficacy studies in animal models may provide sufficient information for approval of ChAdOx1 NiV, the team noted.
Nipah virus (NiV) is a highly pathogenic and re-emerging virus that causes sporadic but severe infections in humans. Currently, no vaccines against NiV have been approved.
Last week, the virus had claimed the life of a 12-year-old boy in Kerala's Kozhikode district. An outbreak of the virus in the state in 2018 had killed 17 of the 18 confirmed with the virus.