Scientists identify world's newest — and rarest — blood type

Most people know of the few main blood types: A, B, O, AB - plus or negative - but scientists have identified dozens of others. Most recently, a team of French researchers discovered a 48th blood type. A woman from Guadeloupe is the only known person with Gwada-Negative, making it not only the newest, but also the rarest, blood group in the world. The World's Host Carolyn Beeler spoke to Martin Olsson. He's a professor of transfusion medicine at Lund University in Sweden.