Scientists Searching for Antibodies Against Deadly Respiratory Disease

Middle East Respiratory Syndrome (MERS) is all over the news right now because the first-ever cases of the disease in the U.S. were found in Indiana and Florida from people who traveled from Saudi Arabia.

The CDC defines MERS as “a viral respiratory illness first reported in Saudi Arabia in 2012. It’s caused by a coronavirus called MERS-CoV. Most people who have been confirmed to have MERS-CoV infection developed severe acute respiratory illness. They had fever, cough, and shortness of breath. About 30 percent of these people died.”

The World Health Organization (WHO) says that currently MERS is not a public health emergency, despite the confusing and often sensationalist headlines all over the news right now.

Dana-Farber Cancer Institute announced in late April that scientists there have identified natural human antibodies against the virus that causes MERS, which, they say, is a “step toward developing treatments for the newly emerging and often-fatal disease.” Currently there is no vaccine or antiviral treatment for MERS.

Research led by Wayne Marasco, an infectious disease expert at Dana-Farber, and reported in the Proceedings of the National Academy of Sciences (PNAS), says that these “neutralizing” antibodies prevented a key part of the virus (MERS-CoV), from attaching to protein receptors that allow the virus to infect human cells.

“This panel of neutralizing antibodies offers the possibility of developing human monoclonal antibody-based immunotherapy, especially for health care workers,” the authors note in the report.

According to the report:

Marasco and colleagues found the MERS antibodies using a “library” of some 27 billion human antibodies that they have created and maintain in a freezer at Dana-Farber; it is one of the largest such libraries in the world. Antibodies are proteins made by the immune system that recognize foreign viruses and bacteria. A neutralizing antibody is one that not only recognizes a specific virus but also prevents it from infecting host cells, so eventually the infection is “cleared” from the individual. The research team plucked seven MERS-specific neutralizing antibodies from the library after using samples of the virus to screen for them.

The researchers selected one of the antibodies, labeled 3B11, as a “lead” candidate for further research. Marasco said the antibody has been produced in sufficient quantities to begin testing in non-human primates and mice to determine if they protect against the virus. However these studies have been delayed because no good animal model for MERS has been developed.

Marasco added in the report that an antibody-based treatment for MERS would be administered by injection and could provide protection for about three weeks. Further experiments are underway that could lead to development of antibody preventives and treatments for MERS.