Scientists are concerned about the mutations happening in the H5N1 virus — more commonly known as bird flu. This week, the European Center for Disease Prevention and Control warned that new mutations in the virus could allow it to spread more easily to humans. About 70 people are known to have been infected in North America alone. The World’s Host Carolyn Beeler spoke to Seema Lakdawala, co-director of the Center for Transmission of Airborne Pathogens at Emory University. She joined the show from Atlanta, Georgia.