Adept antibodies: Antibodies (red) bind to part of a viral protein (yellow and blue).
Fighting the Flu
Newly made antibodies protect against multiple varieties of flu.
Source: “Structural and Functional Bases for Broad-Spectrum Neutralization of Avian and Human Influenza A Viruses”
Jianhua Sui et al.
Nature Structural and Molecular Biology 16: 265-273
Results: Scientists have developed antibody proteins that can neutralize multiple strains of the influenza virus, including common seasonal strains, the deadly H5N1 bird flu, and the virus behind the 1918 epidemic.
Why it matters: Most flu vaccines are effective against only a specific strain of flu; they must be reformulated every year, because they target a part of the virus that constantly mutates to produce new seasonal strains. But the new antibodies target a part of the virus that is common to different strains, so they appear to be broadly effective.
Methods: Scientists first screened billions of antibodies and found a small group that protected against different types of bird flu. Three of these had broad neutralizing abilities when tested in cells and in mice. By looking at the structure of the successful antibodies and analyzing the way they bind to viruses, the scientists identified a part of a protein on the virus’s surface that is shared by different strains of influenza.
Next steps: Researchers will test the antibodies in ferrets, the “gold standard” animal model for influenza, and then develop clinical-grade versions for human testing.