1918 flu virus - riddle solved
Scientists from the MRC's National Institute for Medical Research (NIMR) have solved an 85-year-old mystery by revealing the modus operandi of the world's most lethal influenza outbreak. The first step in infection by flu viruses is their attachment to the cells in which they will replicate themselves. Attachment involves spike-like molecules called haemagglutinins (HA) that project from the viruses and bind to particular receptors on the surface of cells in the body. Using X-ray crystallography to determine the structure of the 1918 virus’ HA, the work provides evidence that the ‘Spanish Flu’ epidemic, which killed an estimated 40 million people worldwide, was triggered when a bird flu virus jumped the species barrier to humans. Understanding the 1918 virus could help scientists understand how bird viruses mutate into forms that can affect humans.
Science 2004; 303: 1838-1842