san francisco mayor tweeter -- tweeted 80% of san francisco residents are vaccinated and this was a major milestone for the city -- what do you make of the milestone as we double down of these vexing -- on these vaccination efforts? dr. rutherford:. rutherford:. r: we need to look at what proportion of everybody is vaccinated in san francisco. we can cut out the under six-month old's, but everyone else is biologically susceptible, so we have to look at that carefully. you have to pay attention to what the denominators are here. if it is 80% of everybody in san francisco, that is great -- we are inching toward herd, witchel probably be -- which will probably be 84% or so. if it is 80% of eligible, we have to add in those ineligible. in san francisco it is a small number because i think everybody work rises san francisco is -- everybody recognizes you don't have millions of kids in san francisco. julian: certainly. again, we are live with dr. george williford. the conversation continues on still with ucsf epidemiologist dr. george rutherford. we have been hearing a lot about ivermectin. how