Universal Flu Vaccine Close At Hand
Major worries over the threat of the highly-lethal H5N1 bird flu and the "Spanish Flu" strain that killed tens of millions in 1918 are close to being put to rest thanks to the possibility of a universal flu vaccine.
Scientists recently unveiled lab-made human antibodies that can disable several types of influenza. The study was conducted in mice; clinical trials on humans could begin within a couple of years, the researchers said.
According to the study, the antibodies work by binding to a previously obscure structure in the flu virus which, when blocked, sabotages the pathogen’s ability to enter the cell it is trying to infect.
This structure is genetically stable and has resisted mutation over time.
The breakthrough "holds considerable promise for further development into a medical tool to treat and prevent seasonal as well as pandemic influenza," said Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
Seasonal flu causes the death of more than 250,000 people every year, and pandemic flu remains an ever-present threat.
Vaccines have long been the first line of defense against flu, but they are not always effective because seasonal viruses evolve rapidly.
Wayne Marasco, a professor at Harvard Medical School, began the study in the laboratory by scanning tens of billions of monoclonal antibodies.
Antibodies are specialized proteins that seek out and bind to other large molecules, called antigens, found on the surface of an invading bacteria or virus.
Monoclonal antibodies are manufactured in the laboratory from a single parent cell using a technique devised more than 30 years ago. In cancer treatment, they help the immune system focus on the right target.
Marasco and his team turned up 10 of the artificial antibodies that bound to the H5N1 avian flu.
The study was published in the journal Nature Structural and Molecular Biology.
The scientists found three of these monoclonal antibodies neutralized 10 of 16 influenza "A" viruses including H5N1.
Only people who have been around infected fowl have become infected with this deadly strain. Yet, scientists worry a future mutation could "jump species" and transfer to humans.
The results were groundbreaking because a single type of antibody focused on different strains of virus, and had disarmed the pathogens on its own without having to call in immune system reinforcements.
Marasco teamed up with researchers at the Infectious and Inflammatory Disease Center in La Jolla, California to find out how this was possible.
Researchers found that by attaching to a poorly understood part of a protein called hemagglutin on the surface of the virus, the lab-made antibody disabled the pathogen’s ability to change shape and enter into the host cell.
"We believe … the hemagglutin protein acts as a decoy by constantly undergoing mutation and thereby attracting the immune system to produce antibodies against it rather than against the pocket in the neck of the protein," Marasco said.
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