New research led by Duke University in collaboration with the University of North Carolina at Chapel Hill (UNC) has found a cross-reacting antibody that significantly limits the severity of infection from various coronaviruses, including SARS-CoV-1 and SARS-CoV-2.
“This antibody has the potential to be a therapeutic for the current epidemic,” said study co-author Barton Haynes, director of Duke Human Vaccine Institute. “It could also be available for future outbreaks, if or when other coronaviruses jump from their natural animal hosts to humans.”
Haynes and his colleague identified and isolated the antibody by analyzing blood samples from a patient infected with SARS-CoV-1, the virus that caused the SARS outbreak in 2003, and from a current COVID-19 patient.
From the total of 1,700 identified antibodies, the researchers found 50 antibodies that could bind to both SARS-CoV-1 and SARS-Cov-2. Further investigations discovered that one of these antibodies was especially potent, being able to bind to a large variety of animal coronaviruses in addition to those affecting humans.
“This antibody binds to the coronavirus at a location that is conserved across numerous mutations and variations. As a result, it can neutralize a wide range of coronaviruses,” Haynes explained.
After they identified and isolated this antibody, Haynes and his colleagues from UNC tested it in mice in order to find out whether it could block infections or minimize them once they occurred. As expected, the antibody protected mice from getting infected if given before they were exposed to coronaviruses, and reduced the severity of symptoms when given after infections. Its range of protection extended to current SARS-CoV-2 variants, including the highly infectious Delta.
“The findings provide a template for the rational design of universal vaccine strategies that are variant-proof and provide broad protection from known and emerging coronaviruses,” said study co-author Ralph Baric, a professor of epidemiology at UNC.
“The therapeutic activity even after mice were infected suggests that this could be a treatment deployed in the current pandemic, but also stockpiled to prevent the spread of a future outbreak or epidemic with a SARS-related virus,” added study co-lead author David Martinez, a postdoctoral fellow at UNC.
“This antibody could be harnessed to prevent maybe SARS-CoV-3 or SARS-CoV-4,” he concluded.
The study is published in the journal Science Translational Medicine.