How concerned should U.S. be about Zika virus outbreak?

The World Health Organization will convene an emergency committee meeting Monday to address the Zika virus outbreak. The mosquito-borne virus appears to be linked to birth defects in newborns. Health officials warned that as many as four million people in the Americas could be infected by the end of the year. CBS News chief medical correspondent Dr. Jon LaPook and CBS News contributor Dr. Holly Phillips joins “CBS This Morning: Saturday” to discuss how concerned people should be.