Researchers at the Dana-Farber Cancer Institute, Boston, the Burnham Institute for Medical Research, La Jolla, Calif, and the Centers for Disease Control and Prevention (CDC) reported the identification of human monoclonal antibodies (mAb) that neutralize an unprecedented range of influenza A viruses, including avian influenza A (H5N1) virus, previous pandemic influenza viruses, and some seasonal influenza viruses. These antibodies have the potential for use in combination with other treatments to prevent or treat certain types of avian and seasonal flu.
The antibodies identified by the researchers neutralize a broad range of influenza A subtypes because they bind to the highly conserved stem region of H5 type hemaglutinin (HA). This prevents a conformational change in the protein that is necessary for viral entry into the host cell, thereby preventing further infection of host cells and the rise of escape mutants.
Although it is more costly to produce therapeutic antibodies than existing influenza drugs, the antibodies can be readily manufactured and stockpiled. In the event of a pandemic, the antibodies could be used in combination with antiviral therapies to contain the outbreak until a vaccine became available. The production of a new influenza vaccine takes 6 to 9 months using conventional methods.
"There are clear settings where human monoclonal antibodies can be used strategically for both the prevention and early treatment of influenza infection and disease," said Wayne A. Marasco, MD, PhD, associate professor of medicine at Dana-Farber and Harvard Medical School. "At-risk individuals, such as first responders and medical personnel, exposed family members and coworkers and patients who cannot make antibodies because of pre-existing medical conditions or advanced age, could all benefit from this new type of therapy."
The study was published online on February 22 in Nature Structural and Molecular Biology.