Labor Day brings new concerns about coronavirus resurgence in the fall

02:54

Top U.S. officials are urging Americans to observe social distancing during Labor Day weekend, or risk kick-starting coronavirus infections in the fall. Meanwhile, researchers at Oxford University have teamed with pharmaceutical giant AstraZeneca to carry out Phase 3 clinical trials of a possible coronavirus vaccine in the U.S. starting Wednesday. NBC national correspondent Miguel Almaguer reports for TODAY.