<p>Researchers have identified a previously unrecognized class of antibodies—immune system proteins that protect against disease—that appear capable of neutralizing multiple forms of flu virus. These findings, which could contribute to development of more broadly protective flu vaccines, will publish December 21<sup>st</sup> by Holly Simmons of the University of Pittsburgh School of Medicine, US, and colleagues in the open access journal <em>PLOS Biology</em>.</p>