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

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, a research scientist at university of san francisco, says there's some things to keep in mind. >> there's two things to be aware of when it comes to picking a material. the first is breakability. and the second is, does it stop liquid? iversity study from 2009 tested the efficiency of homemade masks. and it turns out household products like dish towels and vacuum bags are actually usable. from their analysis, there are many fabric types that will work. if sewing is completely out of the question, which let's be honest -- >> we're going to fold this over -- >> in the, it's better than nothing category, this hair tie and folded cloth option will suffice in a pinch. so if you are making your own mask at home, some advice. be sure to use different fabrics on the front and the back so that when you take it on and off, you know which side should face your mouth when you put it back on. remember to wash them. above all, of course, health officials say nothing works better than social distancing and washing your hands. >> that's for sure. >> yeah, i feel like i'm going to take

jeremy howard, university of san francisco research scientist. a member of world economic forum global council. kind enough to join us via skype. jeremy, maybe you can help me with this, little more than couple weeks ago, we were told save masks for health care workers, average folks walk around really don't need them. what is the real skinny? >> charles, the real skinny is this, super simple. there are hospital masks needed for hospital workers. they do special procedures aerosol generating procedures, spray goes everywhere, you need specially fitted masks. they need them. there is kind of mask you can make at home, don't even need a sewing machine, anybody has to wear the masks to go outside. it is number of one thing we can do to stop the spread of the virus. neil: so, if there is a guideline change, let's say from the surgeon general's office or now the government, i don't know which entity would officially say it is a good idea? i even see, jeremy, more people walking around with these things. i live in a small community. i'm seeing more of

. >> reporter: jeremy howard, a research scientist at the university of san francisco says the rationale for the public wearing the face coveringsu fin making an effective one? the basic pattern is not new. two layers of fabric, three folds, elastic to go around the ears. absent guidance from the cdc i'm bur two ieeen able t that's usable. you can hand sew one. it just taking a little longer. tah-dah. when it comes to choosing a fabric -- >> there's two things to be aware of when it comes to picking material. the first is breathability and the second is does it stop liquid. >> reporter: a cambridge university study from 2009 tested the efficiency of homemade masks and named dish towels and vacuum bags as usable. and from their analysis there are many fabric types that will work. and if sewing is totally out of the question -- >> we're going to fold this over. >> reporter: in the it's better than nothing category this hair tie and folded cloth option will suffice in a pinch. to make it clear, there is no recommendation so far for ordinary citizens to wear a mask. in fact, the state depart

weave doctor jeremy howard now from the university of san francisco speaking to cnn this moing about why the cdc first commended the people, not wear masks and why they change their mind. >>mister howard the w 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 it so wrong. >>well we now know about 50% of people that are infected have no symptoms. we also know that dung the first week is when people are most infectioushen they're least lily to have simpson's some of the w h o did here was that they did not err on the side of caution they were quite sure of the scienceand so they said don't direct but they should have said is due to it because not what we now knowis always strongly. cass isthat if 80% of people in a community where a face mask, any kind of cloud cover that can actually stop the virus its tracks. >>so instead we were doing this,you know a month ago better late an never in this case as opposed to what we can now that we know what to do and if u do need help getting through this because you