today we have oakland mayor libby shaff to discuss a variety of issues from potholes and sidewalks to violence and homeless encampments. it's all on the table. first, lots of covid-19 news today, so we'll begin with usf drchltd peter jin hong. nice to see you. >> thanks for having me on. >> let's get started. the uk is preparing for human challenge trials that will deliberately infect people with the coronavirus. people see the headline are asking why, what is this is all about? >> well, they're going to take people age 18 to 30, basicallyay in london, one of theirs, and find -- and give them a small dose of veergirus, see what syms they get and test them vaccine versus placebo. >> so is the idea that by purposely infecting people as opposed to just giving them vaccine and wait for them to somehow catch it in the community, by giving it to them in a controlled environment, does that somehow speed up the whole process of whether a vaccine is did and can be released to all? >> so basically what will happen is you have a certain duration of time that you can get beyond to foster people i