For the first time since March 2020, San Francisco General Hospital reported zero Covid-19 patients on May 20, 2021. “This is a huge milestone in the pandemic to show the power of the effectiveness of the vaccines,” said Monica Gandhi, an infectious disease expert at University of California San Francisco and medical director of the HIV Clinic at the hospital. She said that 76 percent of San Francisco residents 16 and older have received at least one dose of the coronavirus vaccine. Dr. Sumant Ranji in the hospital's division of hospital medicine said he distinctly remembers hearing of the first coronavirus case in San Francisco and how little everyone knew then. "I think about how much we have learned and how much the community has come together to turn the tide on this pandemic, and it’s really gratifying," he said.