thank you so much for your time today, professor melinda mills said from the university of oxford.ump has appeared in public for the first time wearing a face mask, during a visit to a military hospital in maryland. the visit comes as the us declared a record 66,000 cases of infections in one day. mr trump had previously refused to wear a mask in front of cameras. john mcmanus has the latest. an unexpected change of direction — president trump wearing a face mask in public for the first time. although he recently said that he thought he resembled the lone ranger when he donned a face mask, he originally refused to wear one. i think wearing a face mask as i greet presidents, prime ministers, dictators, kings, queens — i don't know. somehow, i don't see it for myself. the president's change of heart comes as covid—i9 tightens its grip on the us. so far, there have been 135,000 deaths from the virus. with 3.2 million cases, the us is the worst—hit country, and the numbersjust keep on rising. florida is one of those states struggling to contain the virus. after attempting to open in ma

i've been speaking to professor melinda mills.royal society on the behaviour and evidence around face coverings and masks we did a systematic review not only of medical studies but of thousands of studies that have been conducted during sars, hini and covid. two things are clear, one thing is to protect you but most importantly if you are wearing the right kind of mask and protect others. it is very clear and we hear this sort of comments today that it shouldn't be made mandatory but we might encourage it, we saw for the first time borisjohnson wearing a face mask on monday and donald trump is now wearing one. i mean, this is really confusing for the public. what our study showed is that you really have to have really clear policy mandates. even in some countries they have introduced fines. if you have these vague recommendations it is not helpful. people need to know what to wear. it is not about competing with ppe or surgicalface masks. it is really high fabric and a good quality multilayered masks. they need to know when to wea