1 00:00:05,640 --> 00:00:10,639 Speaker 1: Welcome to Prognosis. I'm Laura Carlson. It's day one and 2 00:00:10,760 --> 00:00:16,040 Speaker 1: eighty nine since coronavirus was declared a global pandemic. Today's 3 00:00:16,040 --> 00:00:20,000 Speaker 1: main story. The more we learn about the virus, the 4 00:00:20,079 --> 00:00:24,480 Speaker 1: more ways we have to shift our behavior. The latest surprise, 5 00:00:25,480 --> 00:00:29,600 Speaker 1: how loud we speak may matter for limiting the spread 6 00:00:29,600 --> 00:00:34,920 Speaker 1: of the virus. But first, here's what happened in virus 7 00:00:34,960 --> 00:00:48,680 Speaker 1: news today. Top US health officials offered conflicting estimates of 8 00:00:48,720 --> 00:00:54,200 Speaker 1: when Americans should expect a widely available coronavirus vaccine. In 9 00:00:54,200 --> 00:00:58,160 Speaker 1: an interview today, Paul Mango, Deputy Chief of Staff for 10 00:00:58,280 --> 00:01:02,240 Speaker 1: Policy at the Department of Health and Human Surfaces, offered 11 00:01:02,360 --> 00:01:07,840 Speaker 1: a very ambitious timetable. He said every American could be 12 00:01:07,880 --> 00:01:10,479 Speaker 1: able to get a shot by the end of March. 13 00:01:12,560 --> 00:01:16,039 Speaker 1: His remarks came after President Donald Trump set in a 14 00:01:16,120 --> 00:01:20,480 Speaker 1: televised town hall event last night that a vaccine could 15 00:01:20,520 --> 00:01:25,759 Speaker 1: be approved in three or four weeks. But the director 16 00:01:25,800 --> 00:01:29,479 Speaker 1: of the Centers for Disease Control and Prevention, Robert Redfield, 17 00:01:29,520 --> 00:01:34,160 Speaker 1: gave Senate testimony today and he was less optimistic than 18 00:01:34,280 --> 00:01:39,240 Speaker 1: Mango or Trump. His estimate was that most Americans wouldn't 19 00:01:39,280 --> 00:01:42,240 Speaker 1: be able to get a shot of an effective vaccine 20 00:01:42,640 --> 00:01:48,200 Speaker 1: until the second or third quarter of next year. Astra 21 00:01:48,320 --> 00:01:53,160 Speaker 1: Zenica's vaccine trial remains paused in the US for a 22 00:01:53,200 --> 00:01:58,320 Speaker 1: regulatory review of an incident where a participant developed unexplained 23 00:01:58,520 --> 00:02:04,920 Speaker 1: neurological symptoms, including limb weakness, but the company said the 24 00:02:05,000 --> 00:02:09,840 Speaker 1: symptoms probably weren't related to the shot itself. That's according 25 00:02:09,880 --> 00:02:13,280 Speaker 1: to a letter the company sent to participants in the study. 26 00:02:13,840 --> 00:02:19,240 Speaker 1: The letter reads quote After considering the information, the independent 27 00:02:19,280 --> 00:02:26,120 Speaker 1: reviewers recommended the vaccinations should continue. India's virus cases reached 28 00:02:26,320 --> 00:02:29,639 Speaker 1: the five million mark with the addition of more than 29 00:02:29,760 --> 00:02:33,799 Speaker 1: ninety thousand new cases. The virus has been spreading in 30 00:02:33,800 --> 00:02:37,160 Speaker 1: India at one of the fastest paces in the world. 31 00:02:38,040 --> 00:02:41,600 Speaker 1: India has the third highest death toll from COVID nineteen, 32 00:02:42,200 --> 00:02:47,200 Speaker 1: trailing the US and Brazil. The real number of infected 33 00:02:47,400 --> 00:02:51,240 Speaker 1: and dead in India from COVID nineteen is likely far 34 00:02:51,440 --> 00:02:55,440 Speaker 1: higher than the official numbers due to under reporting and 35 00:02:55,600 --> 00:03:01,400 Speaker 1: inadequate testing. India's strict lockdown in clemented in late March 36 00:03:01,520 --> 00:03:05,280 Speaker 1: to contain the outbreak, led to the biggest economic contraction 37 00:03:05,520 --> 00:03:18,000 Speaker 1: of any major economy and now for today's main story. 38 00:03:19,600 --> 00:03:22,200 Speaker 1: We've heard there are many things we can do to 39 00:03:22,280 --> 00:03:26,120 Speaker 1: reduce the spread of the coronavirus, staying six ft away 40 00:03:26,120 --> 00:03:30,120 Speaker 1: from someone else, washing our hands, and wearing a mask. 41 00:03:30,919 --> 00:03:35,200 Speaker 1: But there's something else we can also do. Talk less. 42 00:03:36,040 --> 00:03:40,280 Speaker 1: Speaking is a powerful generator of aerosols, the fine particles 43 00:03:40,280 --> 00:03:43,240 Speaker 1: emitted from our mouths that can harbor the stars Cove 44 00:03:43,440 --> 00:03:49,320 Speaker 1: two virus and potentially linger for hours in poorly ventilated spaces. 45 00:03:50,280 --> 00:03:54,880 Speaker 1: Turns out, shutting up can help shut those particles down, 46 00:03:55,920 --> 00:03:59,840 Speaker 1: and as Bloomberg Senior editor Jason Gale found out, it 47 00:04:00,040 --> 00:04:04,240 Speaker 1: few must speak. It's safer if you do it softly. 48 00:04:14,080 --> 00:04:17,560 Speaker 1: Aerosols are tiny particles emitted from our respiratory tracks that 49 00:04:17,680 --> 00:04:21,479 Speaker 1: can stay aloft in ambient air for hours. There's been 50 00:04:21,680 --> 00:04:24,480 Speaker 1: some debate about the role virus, light and eborne particles 51 00:04:24,560 --> 00:04:28,200 Speaker 1: play and transmitting the COVID nineteen causing coronavirus. So I 52 00:04:28,279 --> 00:04:31,120 Speaker 1: asked Bill Riston, party, professor of chemical engineering at the 53 00:04:31,200 --> 00:04:35,039 Speaker 1: University of California, Davis, what we know about aerosols in 54 00:04:35,080 --> 00:04:38,640 Speaker 1: the spread of the pandemic disease. That's a complicated question, 55 00:04:38,680 --> 00:04:41,280 Speaker 1: of course, right because the contact racing referred so much 56 00:04:41,279 --> 00:04:43,839 Speaker 1: about that that tells you who you likely got it 57 00:04:43,880 --> 00:04:45,480 Speaker 1: from and when you likely got it, but it does 58 00:04:45,520 --> 00:04:48,279 Speaker 1: not tell you by itself how you got it, whether 59 00:04:48,320 --> 00:04:50,880 Speaker 1: those through a handshake or through them coughing your face 60 00:04:51,040 --> 00:04:55,480 Speaker 1: or just talking and releasing infectious aerosol particles that travel 61 00:04:55,520 --> 00:04:59,920 Speaker 1: across the room. But the indirect evidence implicating aerosols is mounting. 62 00:05:00,400 --> 00:05:01,960 Speaker 1: The very first one that opened a lot of people's 63 00:05:02,000 --> 00:05:04,760 Speaker 1: eyes was that outbreak of the choir practice up at 64 00:05:04,760 --> 00:05:08,560 Speaker 1: Washington State. I think it was of the people who 65 00:05:08,560 --> 00:05:11,760 Speaker 1: attended got infected just during a two n fur choir practice, 66 00:05:12,200 --> 00:05:16,200 Speaker 1: and you know choir practice that's associated with loud vocalization. 67 00:05:16,400 --> 00:05:20,000 Speaker 1: Then there was the Knees lunch in a restaurant in Guango, China, 68 00:05:20,360 --> 00:05:23,400 Speaker 1: in which Tan Dinas came down with COVID nineteen. They 69 00:05:23,400 --> 00:05:25,400 Speaker 1: had video evidence, which is really great. They showed that 70 00:05:25,480 --> 00:05:28,560 Speaker 1: some of the people who got infected did not directly 71 00:05:28,600 --> 00:05:32,760 Speaker 1: interact with the index case except by a virtue of 72 00:05:32,760 --> 00:05:35,280 Speaker 1: the fact they're sharing the same air. Um, so they 73 00:05:35,320 --> 00:05:38,120 Speaker 1: like did not you know, talk that didn't face to 74 00:05:38,160 --> 00:05:40,920 Speaker 1: face and all that. So that's another piece of evidence 75 00:05:40,960 --> 00:05:45,080 Speaker 1: for some type of long range transmission, and the expertory 76 00:05:45,080 --> 00:05:50,080 Speaker 1: particles is the prime suspect. Then there have been outbreaks 77 00:05:50,080 --> 00:05:53,320 Speaker 1: and bars whole Center and a cafe in South Korea 78 00:05:53,520 --> 00:05:56,560 Speaker 1: and a bus in China. The whole focused attention on 79 00:05:56,640 --> 00:06:01,440 Speaker 1: potentially infectious particles emitted from the respiratory tract. I asked Bill, 80 00:06:01,640 --> 00:06:04,280 Speaker 1: how are these produced? There's at least three modes of 81 00:06:04,880 --> 00:06:09,680 Speaker 1: respiratory droplet or respiratory particle generation. You know, sometimes you're 82 00:06:09,680 --> 00:06:11,839 Speaker 1: you're talking and you see little drops of fluid come out. 83 00:06:12,279 --> 00:06:15,000 Speaker 1: That's the so called oral mode, and that's mostly saliva um, 84 00:06:15,279 --> 00:06:18,120 Speaker 1: an old fashioned word to spittle. Those those droplets if 85 00:06:18,160 --> 00:06:20,640 Speaker 1: you can feel them hitting somebody or if you can 86 00:06:20,680 --> 00:06:23,760 Speaker 1: see them. Relatively speaking, they're huge, way bigger than like say, 87 00:06:23,800 --> 00:06:26,440 Speaker 1: fifty micrones, So they're like big boulders basically. And that's 88 00:06:26,440 --> 00:06:29,520 Speaker 1: just one mode. The other two modes refer to much 89 00:06:29,560 --> 00:06:32,240 Speaker 1: smaller particles that you can't see with the naked eye. 90 00:06:32,720 --> 00:06:34,960 Speaker 1: One of them comes from the campillaries that line the 91 00:06:35,000 --> 00:06:37,840 Speaker 1: bronchials in the far reaches of the lungs. When you 92 00:06:37,920 --> 00:06:41,159 Speaker 1: exhale and you squeeze everything down your lungs, these little 93 00:06:41,200 --> 00:06:44,960 Speaker 1: capillaries come together, kind of pinched together, and then you 94 00:06:45,000 --> 00:06:49,120 Speaker 1: inhale and they expand and there's respiratory fluid lining those. 95 00:06:49,120 --> 00:06:51,800 Speaker 1: And so when you do that in expanse, you have 96 00:06:51,839 --> 00:06:54,719 Speaker 1: a little fluid film that kind of pinches off and 97 00:06:54,800 --> 00:06:58,200 Speaker 1: leaves little satellite droplets, your daughter droplets that are now 98 00:06:58,839 --> 00:07:01,880 Speaker 1: exhaled with your air. Bill says, these particles are about 99 00:07:01,960 --> 00:07:04,800 Speaker 1: one micron in diameter. You know, I don't have much hair, 100 00:07:04,880 --> 00:07:07,880 Speaker 1: but a typical human hair is about a hundred microns, 101 00:07:08,080 --> 00:07:10,040 Speaker 1: so it's a hundred times smaller than the diameter of 102 00:07:10,400 --> 00:07:12,880 Speaker 1: human hair. And so just breathing releases some of those. 103 00:07:13,360 --> 00:07:16,320 Speaker 1: The other the third and final mode is the larrangel mode, 104 00:07:16,360 --> 00:07:21,040 Speaker 1: so at the vocal chords. So when somebody says, uh, 105 00:07:21,200 --> 00:07:24,280 Speaker 1: what's actually happening is you have these like little vocal 106 00:07:24,400 --> 00:07:27,520 Speaker 1: words are opening and shutting at the frequency of your 107 00:07:27,800 --> 00:07:30,119 Speaker 1: your pitch right, So I have kind of a deep voice. 108 00:07:30,440 --> 00:07:32,360 Speaker 1: It's about a hundred twenty hurts. That means when I'm 109 00:07:32,360 --> 00:07:34,960 Speaker 1: saying uh, literally, it's going like this a hundred twenty 110 00:07:34,960 --> 00:07:38,760 Speaker 1: times a second. And these also have fluid lighting them. 111 00:07:38,760 --> 00:07:40,840 Speaker 1: I should add here that Bill's lab has two high 112 00:07:40,880 --> 00:07:44,160 Speaker 1: speed cameras that can capture images at more than one 113 00:07:44,240 --> 00:07:47,760 Speaker 1: hundred thousand frames per second. He also has various optical 114 00:07:47,800 --> 00:07:50,680 Speaker 1: and laser systems for visualizing the micro droplets that have 115 00:07:50,800 --> 00:07:53,600 Speaker 1: created when we speak. So right now, as I've been talking, 116 00:07:53,680 --> 00:07:56,640 Speaker 1: I've been emitting particles in the room right in front 117 00:07:56,680 --> 00:07:58,400 Speaker 1: of me. And even though they're really tiny, too tiny 118 00:07:58,560 --> 00:08:01,680 Speaker 1: to see, they're huge compared to the virus. So the 119 00:08:01,760 --> 00:08:04,440 Speaker 1: virus can very happily be carried along in these micron 120 00:08:04,520 --> 00:08:07,080 Speaker 1: skill So you have like a little little tiny bits 121 00:08:07,400 --> 00:08:09,920 Speaker 1: of stunt, you know, basically floating around in the air 122 00:08:09,960 --> 00:08:14,119 Speaker 1: that could be carrying the virus. The Bill's researchers showing 123 00:08:14,160 --> 00:08:17,680 Speaker 1: that certain things can vary the emission of expertory particles. 124 00:08:18,480 --> 00:08:22,640 Speaker 1: We found that speaking releases much more than breathing. And 125 00:08:22,800 --> 00:08:24,560 Speaker 1: we went even further, and what we showed is that 126 00:08:24,720 --> 00:08:27,760 Speaker 1: like how many particles emitted doing speech is a very 127 00:08:27,840 --> 00:08:30,480 Speaker 1: strong function of how loud you are. So if you 128 00:08:30,520 --> 00:08:33,120 Speaker 1: speak really loud, you emit a ton of way more 129 00:08:33,160 --> 00:08:34,800 Speaker 1: than if you than if you required if you whisper. 130 00:08:35,520 --> 00:08:39,160 Speaker 1: And some folks just emit a lot of particles. Bill says, 131 00:08:39,200 --> 00:08:43,520 Speaker 1: some people are super emitters. So for whatever reason, um, 132 00:08:43,600 --> 00:08:46,120 Speaker 1: some individuals when they talk just amit an order of 133 00:08:46,160 --> 00:08:50,240 Speaker 1: magnitude more factor tend more than other people. And Bill 134 00:08:50,280 --> 00:08:53,520 Speaker 1: says when some people cough for whatever reason, why more 135 00:08:53,640 --> 00:08:58,559 Speaker 1: comes out. But these supermit is super spreaders of the coronavirus. 136 00:08:59,160 --> 00:09:02,559 Speaker 1: That's a very challenge hypothesis to test post facto from 137 00:09:02,559 --> 00:09:07,800 Speaker 1: an outbreak, but it's definitely a hypothesis that wants more investigation. 138 00:09:07,960 --> 00:09:09,840 Speaker 1: If I was the virus in China affect as many people, 139 00:09:09,840 --> 00:09:12,120 Speaker 1: I'd want to a super emitter who also was a 140 00:09:12,120 --> 00:09:15,000 Speaker 1: super grower the virus, or like the virus was very successful, 141 00:09:15,080 --> 00:09:18,240 Speaker 1: so you had a very high viral concentrations. And then 142 00:09:18,240 --> 00:09:19,640 Speaker 1: I make sure if I was a virus again that 143 00:09:19,800 --> 00:09:23,040 Speaker 1: I didn't make the person symptomatic, so they looked very healthy. 144 00:09:23,120 --> 00:09:25,160 Speaker 1: And I'd have them go to a bar or a 145 00:09:25,240 --> 00:09:27,600 Speaker 1: choir practice and have them sing and just vocalize as 146 00:09:27,640 --> 00:09:30,240 Speaker 1: much as possible for a very long time. And I'd 147 00:09:30,240 --> 00:09:32,400 Speaker 1: also tell the people to shut off the ventilation, uh 148 00:09:32,440 --> 00:09:35,240 Speaker 1: so so that you know, to get the airborne viral 149 00:09:35,280 --> 00:09:38,040 Speaker 1: concentration as high as possible. But also found that saying 150 00:09:38,080 --> 00:09:42,320 Speaker 1: certain words it's associated with more particles admitted employs. It's 151 00:09:42,400 --> 00:09:46,480 Speaker 1: like Papa produced more than fricatives like fafa but in 152 00:09:46,520 --> 00:09:50,200 Speaker 1: general it was less important. Again if I was if 153 00:09:50,240 --> 00:09:51,839 Speaker 1: I was a virus, I wouldn't care so much about 154 00:09:51,960 --> 00:09:54,920 Speaker 1: what the word you're saying is. I would want to 155 00:09:54,920 --> 00:09:57,480 Speaker 1: be in somebody who's saying it loudly. Right, So, in 156 00:09:57,520 --> 00:10:01,600 Speaker 1: other words, minor changes and how loud you're articulating swamp 157 00:10:01,640 --> 00:10:04,960 Speaker 1: out of the differences and what you're articulating. Does this 158 00:10:05,000 --> 00:10:08,760 Speaker 1: mean people should be quiet for the sake of public health. 159 00:10:09,600 --> 00:10:12,080 Speaker 1: I was advocating to some journalists who interviewed me back 160 00:10:12,120 --> 00:10:14,920 Speaker 1: in April, and I said, I think we should start 161 00:10:14,960 --> 00:10:19,040 Speaker 1: thinking about recommending people don't talk so much, especially in 162 00:10:19,120 --> 00:10:21,360 Speaker 1: high risk of rooms like hospital wedding rooms. Back then, 163 00:10:21,400 --> 00:10:23,280 Speaker 1: the report is looking at like that's crazy, but I 164 00:10:23,320 --> 00:10:26,920 Speaker 1: think I think there is great to that. Now in September, 165 00:10:27,120 --> 00:10:30,560 Speaker 1: that recommendation is sounding kind of sensible. We know that 166 00:10:30,640 --> 00:10:34,240 Speaker 1: maintaining a physical distance, wearing a face mask, and thorough 167 00:10:34,320 --> 00:10:37,760 Speaker 1: handwashing all helped to reduce the risk of spreading the coronavirus, 168 00:10:38,120 --> 00:10:41,120 Speaker 1: but none is fail safe. It's doing them all together 169 00:10:41,720 --> 00:10:45,400 Speaker 1: and quietly and offers the best chance at driving the 170 00:10:45,400 --> 00:11:06,400 Speaker 1: pandemic into submission. That was Jason Gail, And that's it 171 00:11:06,480 --> 00:11:08,920 Speaker 1: for our show Today. For coverage of the outbreak from 172 00:11:08,920 --> 00:11:12,199 Speaker 1: one D and twenty bureaus around the world, visit bloomberg 173 00:11:12,320 --> 00:11:16,360 Speaker 1: dot com Flash Coronavirus and if you like the show, 174 00:11:16,720 --> 00:11:19,640 Speaker 1: please leave us a review and a rating on Apple 175 00:11:19,720 --> 00:11:23,320 Speaker 1: Podcasts or Spotify. It's the best way to help more 176 00:11:23,360 --> 00:11:27,760 Speaker 1: listeners find our global reporting. The Prognosis Daily edition is 177 00:11:27,800 --> 00:11:32,520 Speaker 1: produced by topor foreheads Jordan gas Pure, Magnus Hendrickson, and 178 00:11:32,640 --> 00:11:37,280 Speaker 1: me Laura Carlson. Today's main story was reported by Jason Gale. 179 00:11:37,800 --> 00:11:42,120 Speaker 1: Original music by Leo Sidrin. Our editors are Rick Shine 180 00:11:42,120 --> 00:11:46,960 Speaker 1: and Francesca Levi. Francesca Levi is Bloomberg's head of podcasts. 181 00:11:47,440 --> 00:11:48,319 Speaker 1: Thanks for listening.