The U.S. began the New Year by reaching more than 20 million COVID-19 infections and a record number of people in hospital. The vaccines that provided a ray of hope are being rolled out much slower than expected. For some analysis of new virus mutation in the U.S. and the rollout of vaccines, CGTN talked with Peter Chin-Hong, a professor of medicine and an infectious disease specialist at the University of California. He said that the virus variant has "certainly" been spreading in U.S. communities for some time.