A study led by researchers at the University of North Carolina Gillings School of Global Public Health found that a SARS-like virus known as WIV1-CoV, which is found in horseshoe bats, could bind to the same receptors as SARS-CoV and replicate in human cells without the need for adaptation. Thought to be a critical barrier, the results indicate that bat populations maintain SARS-like viruses poised to reemerge in humans.
[Photo: Drs. Vineet Menachery (left) and Ralph Baric]
The study, titled “SARS-like WIV1-CoV poised for human emergence,” was published in the latest issue of the Proceedings of the National Academy of Science (PNAS). The study’s primary investigator is Dr. Ralph Baric, professor of epidemiology at UNC.
“This study goes beyond sequence analysis, which clearly has its limits,” Dr. Baric said. “We focused on SARS-like corona viruses isolated from Chinese horseshoe bats, where SARS originated. One that we identified, WIV1-CoV, was a very likely candidate for transmission to humans.”
The research team worked with both full-length and chimeric versions of WIV1-CoV. The virus readily and efficiently replicated in cultured human airway tissues, suggesting the potential ability to jump directly to humans.
The research team also found that monoclonal antibodies developed to treat SARS were effective in both human and animal tissue sample against WIV1-CoV. However, existing vaccines against SARS would not provide protection for this new virus.
SARS (Severe Acute Respiratory Syndrome) was first seen in an outbreak in 2002 and resulted in 8,000 cases and nearly 800 deaths. Spread through airborne contact, its onset presents symptoms similar to the flu with a dry cough but can accelerate rapidly to pneumonia, filling the lungs with fluid and putting extreme stress on the body’s immune system. According to the Centers for Disease Control and Prevention (CDC) SARS’ mortality rate can range from less than one percent in patients younger than 24 years to more than 50 percent in patients ages 60 and older. The researchers involved with the UNC-led study theorized that WIV1-CoV has the potential to induce similar results with proper adaptation to humans.
“There is a subset of coronaviruses currently circulating in bats have the ability to bind and enter human cells,” said Dr. Vineet Menachery, postdoctoral fellow in the Baric Lab at UNC and the study’s first author. “Instead of being the result of a rare mutation, the capacity of this group of viruses to jump into humans is greater than we originally thought.”