“San Francisco is still recording a small number of coronavirus cases, about 13.7 per day, said Dr George Rutherford, professor of epidemiology at University of California San Francisco, but they don’t appear to be gaining enough of a foothold in the population to trigger wider outbreaks. ‘That is what herd immunity looks like,’ Rutherford said. ‘You’re going to have single cases, but they’re not going to propagate out.'” San Francisco may be first major US city to hit herd immunity. (We’re also first in the National League West, baby.)