Zika Virus: How concerned should Americans be?

Dozens of cases of Zika virus in the United States have prompted the Centers for Disease Control's Command Center to go to its highest level. CBS News Chief Medical Correspodent Dr. Jon LaPook discusses his reporting on the Zika virus in Brazil, his discussion with the doctor that found that link between the virus and birth defects. Watch his discussion with CBSN's Elaine Quijano.