A novel synthetic DNA vaccine for Middle East Respiratory Syndrome (MERS) can, for the first time, fully protect monkeys against the deadly virus, scientists, including those of Indian-origin, have found.
The experimental, preventive vaccine, given six weeks before exposure to the MERS coronavirus, was found to fully protect rhesus macaques from the disease, researchers said.
The vaccine also generated potentially protective antibodies in blood drawn from camels, the purported source of MERS transmission in the Middle East.
MERS is caused by an emerging human coronavirus. Since its identification in 2012, MERS has been linked to over 1,300 infections and close to 400 deaths. It has occurred in the Arabian Peninsula, Europe, and in the US, researchers said.
The recent 2015 outbreak in South Korea was of great concern as the infection spread from a single patient to infect more than 181 people, resulting in hospital closings, severe economic impact, and more than 30 deaths, they said.
During this outbreak rapid human-to-human transmission was documented with in-hospital transmission the most common route of infection.
"The significant recent increase in MERS cases, coupled with the lack of effective antiviral therapies or vaccines to treat or prevent this infection, have raised significant concern," said David B Weiner, professor at the Perelman School of Medicine, University of Pennsylvania in US.
"Accordingly the development of a vaccine for MERS remains a high priority," Weiner said.
Other researchers involved in the study included Niranjan J Sardesai, Chief Operating Officer at Inovio Pharmaceuticals in US and Ami Patel from University of Pennsylvania.
The vaccine was able to prevent MERS disease in the monkeys and offered benefit to 100 per cent of the animals in this study in terms of minimising symptoms.
In addition, the vaccine induced antibodies that are linked with protection in camels, a species that is thought to be a major source of transmission to humans in the Middle East, showing that this vaccine could be deployed to break this link in the MERS transmission cycle.
In the field, the researchers said, this vaccine could decrease person-to-person spread of infection in the event of an outbreak and help to protect health care workers or exposed individuals.
"This simple synthetic vaccine has the potential to overcome important production and deployment limitations, and what's more, the vaccine is non-live, so does not pose a risk of spreading to unintended individuals," said first author Karuppiah Muthumani, a research assistant professor of Pathology and Laboratory Medicine at University of Pennsylvania.
The study was published in the journal Science Translational Medicine.
