i'm really excited about this joining us is jeremy howard. you've been talking about masks for the past six weeks or more, right? >> right. >> now that we're finally adopting this on a more universal basis, i want to get it to. i'm excited sthoe people how quickly it can be done. before we get to that i know you have been studyig it if people all wore masks and you have the results of a new study. tell us about that. >> since i was last on your show i put together a team from all around the world. south africa, europe. we have been studying the data and literature intensely. we have discovered that people have their masks backwards or inside out. the research has been looking at what's the impact when you wear a masks in terms of do you get sick, do you get infected if you're wearing a mask. what masks do is they stop other people from getting sick if you're sick. remember, you don't know if you're sick. you're most infectious at the time that you've just first been infected. we crunched the numbers and it turns out under some pretty conserva

university of san francisco data scientist and founder of masks for all, jeremy howard, joins us once again. hey, jeremy, good to see you. >> hello there. nice to see you, too. >> i know. i can't wait to get to the mask making because i just think that's so useful for many people. but, first, i would like to clarify for our viewers, under what situations they need to wear a mask now when they're out and about in the bay area. so let's talk about when they're absolutely required. >> yeah. so they're absolutely required, both, legally and practically. they're nicely aligned, which makes it easy. basically, whenever you're out and about, exempt when you're exercising, not when you're at home and not when you're in the car with family members or on your own. in those situations, there is no requirement, under the orders, to wear a mask. >> okay. in fact, you just answered jonathan rosenbaum's question. he asked do i need to wear a mask if i am just going to take a walk around the neighborhood? so yt sai it's not necessary, and of course it's not legally required. but should you? i mean, c

and we're back with jeremy howar howard. the question i'm going to ask, i'm going to pose it here because i want people to know. do you have any hard data that would suggest when you have a critical mass wearing these scarves is effective to tamp down the spread. >> i have a couple of interesting examples of this. perhaps the best thing we can do as data scientists is to look at two time periods of the same country. try and find two time periods but nothing much changes. you can't be perfect. one interesting thing is look at south korea. they have a culture of mask wearing but mainly only when they have symptoms. we now know it's not the primary time they need it. also, the country ran out of masks. people were not able to get masks. during that time, the number of cases in south korea was closely tracking italy. we know how awful things have gotten in italy. then in late february, the government stepped in and they guaranteed a supply of masks and set up a system where everybody could go and get their masks on a particular

jeremy howard is a distinguished research scientist at the university of san francisco. he wrote those words for "the washington post." mr. howard, the w.h.o. initially said you only need to wear a mask if you're taking care of a person with a suspected covid-19 infection. how did they get tell so strong? >> well, we now know that 50% of people infected have no symptoms. we also know during the first week is when people are most infectious, where they're least likely to have symptoms. what the w.h.o. did here, they did not err on the side of caution. they weren't quite sure of the science, and what they should have said is do do it. 80% of americans wear a face mask, any kind of cover, they can actually stop the virus in its tracks. >> here is the cloth covering i'm using, i don't know if you can see it, when i wear it, am i doing so to protect myself or to protect you? >> primary, you're doing it to do your bit in the community to protect others. we know that this disease spreads when we talk, little droplets fly out of our mouth. it makes obvious sense and the science

jeremy howard, really interesting to talk to you about that. thank you so much. the brazilian president, jair bolsonaro, has sacked his health minister after the two men openly clashed over how to tackle the spread of coronavirus. the minister had been an advocate of a lockdown. but the president has called for brazilians to go back to work. mr bolsonaro said brazil‘s economy needed to gradually open up, or the country would go broke. new york‘s governor has extended the stay at home order until may 15. despite the restrictions, the city‘s devoted joggers are finding ways to keep up their regular routines. the bbc‘s tom brook is a runner — he laced up his shoes for a spin around central park, to help bring the pandemic into focus. stopping the spread of the coronavirus is a mission for all of us. the alarm goes off every morning with radio news bringing more gloom. i get up, make some coffee, prepare for my run, don my face mask and go down to the street. i live just 30 seconds from central park. there ijoin other runners. i stop and talk to them, of co

science jeremy howard will answer the questions more. next. ♪ ♪ >> in an ideal world, we would have the public being messed when they go out. >> we don't recommend them for the general public. >> laura: which is that? masks, no masks, halloween masks? while the cdc and settling the debate in recommending and not requiring, people wear face masks while they're out in public in a physical distance, but not the kind that doctors are. >> a scarf is highly recommended by the professionals. >> can be made from bad demos or scarves or things like this which you have at home. >> were advising new yorkers to wear a face covering whether it be a scarf, it can be something you create yourself at home. >> laura: joining me now is jeremy howard, founder of masks for all and university of san francisco scientist and jeremy, should we d be doing a y thing with a vacuum cleaner bags and i'm looking for those all night and i can find any. there's a run on the banks now and apparently that's good. would you recommend? >> you know, the worst mask as yo

scientist jeremy howard will answer all those questions and more next. [ "one more time" by daft punk ] woo! [ laughing ] woo! play pop music! ♪ no way dude, play rock music! yeah! -woah! no matter what music you like, stream it now on pandora with xfinity. and don't forget to catch "trolls world tour". let's party people! ♪ one more time ♪ >> the mask will protect you from a respiratory illness. >> in an ideal world, we'll have the public being mask going out. >> we don't recommend them for the general public. >> laura: which is it, mask, no mask, halloween mask, cloth mask. cdc settling debate and recommending, not requiring it, people wear a mask out in public when they can't physically distance, but not the kind doctors are using. >> a scarf is highly recommended by the professionals. >> it can be made from bandannas or scarfs, things like this that you can have at home. >> we are advising new yorkers to wear a face covering. it could be a scarf. you could be something that you create yourself at home. >> laura: joined me now is jeremy howard, founder of mask for all, a univ