WEBVTT - Who's Really Immune? 0:00:05.640 --> 0:00:10.640 Welcome to Prognosis. I'm Laura Carlson. It's day forty nine 0:00:10.840 --> 0:00:15.400 since coronavirus was declared a global pandemic. Our main story, 0:00:16.079 --> 0:00:19.880 immunity has come up a lot recently as governments consider 0:00:19.920 --> 0:00:25.360 whether and how to reopen. Some have floated immunity passports 0:00:25.720 --> 0:00:28.280 that would allow people who have successfully thought off the 0:00:28.360 --> 0:00:33.400 virus to go back into society. Trouble is that assumes 0:00:33.440 --> 0:00:38.440 an understanding of coronavirus. We still don't have. Whether having 0:00:38.479 --> 0:00:41.800 the virus makes you immune to future infections, and if so, 0:00:42.320 --> 0:00:47.280 for how long is still unclear. So who's really immune? 0:00:47.960 --> 0:01:01.639 But first, here's what happened today. The US recession has 0:01:01.680 --> 0:01:06.960 officially begun. After eleven years of record growth. The economy 0:01:06.959 --> 0:01:10.000 shrank at a four point eight percent annualized rate in 0:01:10.040 --> 0:01:14.280 the first quarter, with a coronavirus forcing businesses to close 0:01:14.600 --> 0:01:18.039 and consumers to stay home around the country. It's likely 0:01:18.080 --> 0:01:21.480 to be the deepest recession in at least eighty years. 0:01:22.400 --> 0:01:28.240 That's right, eighty years. The current quarter is expected to 0:01:28.319 --> 0:01:35.600 be far worse. Bloomberg Economics projects an annualized contraction of 0:01:35.640 --> 0:01:41.440 a staggering thirty seven percent. The Trump administration has launched 0:01:41.440 --> 0:01:45.960 a project to fast track a coronavirus vaccine. The goal 0:01:46.160 --> 0:01:48.880 is to make enough doses for most Americans by the 0:01:49.040 --> 0:01:54.000 end of the year. The program, called Operation Warp Speed, 0:01:54.320 --> 0:01:59.800 will pull together private pharmaceutical companies, government agencies, and the military. 0:02:01.000 --> 0:02:04.360 As part of the arrangement, taxpayers will shoulder much of 0:02:04.400 --> 0:02:08.880 the financial risk that vaccine candidates may fail instead of 0:02:08.960 --> 0:02:13.040 drug companies. There was good news from the pharmaceutical industry 0:02:13.080 --> 0:02:16.520 today which brought hope that the first effective treatment for 0:02:16.560 --> 0:02:23.160 coronavirus could be around the corner. Gilead Sciences said that remdesvie, 0:02:23.560 --> 0:02:26.919 their experimental drug to treat the virus, worked better than 0:02:26.960 --> 0:02:31.880 standard care in a clinical trial. The coronavirus outbreak is 0:02:31.919 --> 0:02:36.519 at different stages around the world. In Europe, some countries 0:02:36.680 --> 0:02:41.040 are seeing fit to loosen restrictions on movement, others fear 0:02:41.080 --> 0:02:47.280 a second wave. France and Spain took cautious steps towards reopening, 0:02:48.200 --> 0:02:51.400 but in Germany new cases rose for the first time 0:02:51.440 --> 0:02:55.320 in three days as the government weighed removing more curbs. 0:02:56.639 --> 0:03:00.639 New York reported a fourth day of declining deaths, though 0:03:00.760 --> 0:03:06.480 new hospitalizations rose slightly. In other regions, the virus is 0:03:06.520 --> 0:03:11.080 taking an even more serious toll. Brazil is rising in 0:03:11.120 --> 0:03:14.560 the ranking of most hit places by the coronavirus. It 0:03:14.680 --> 0:03:17.360 is now the country with the third largest number of 0:03:17.400 --> 0:03:20.880 deaths reported over the past twenty four hours, after the 0:03:20.960 --> 0:03:36.800 US and the UK, and now our main story. As 0:03:36.840 --> 0:03:39.160 states grapple with the question of when it will be 0:03:39.160 --> 0:03:44.160 safe to reopen businesses and relax social distancing, there's increasing 0:03:44.280 --> 0:03:50.000 urgency to better understand who's immune to COVID nineteen. Does 0:03:50.280 --> 0:03:53.640 having the virus and recovering from it mean you can't 0:03:53.680 --> 0:03:56.160 get it again, or at least that you can't be 0:03:56.200 --> 0:04:00.720 reinfected for some time. The problem is no one yet 0:04:00.840 --> 0:04:05.960 has good answers to these questions. Here's Bloomberg reporter Kristin V. 0:04:06.160 --> 0:04:13.440 Brown with more on the science of coronavirus immunity. When 0:04:13.480 --> 0:04:15.880 I was a kid and I got the chicken pox, 0:04:16.320 --> 0:04:18.640 one of the things I remember my mom telling me 0:04:19.080 --> 0:04:21.680 is that I couldn't get the virus that caused the 0:04:21.760 --> 0:04:27.039 chicken pox again. She told me that I was immune. This, 0:04:27.440 --> 0:04:30.880 I think is common wisdom when it comes to viruses. 0:04:32.000 --> 0:04:35.600 That is, after all, how vaccines work. You're exposed to 0:04:35.600 --> 0:04:39.480 a virus like polio or the measles, your immune system 0:04:39.600 --> 0:04:43.000 identifies that virus and figures out how to produce antibodies 0:04:43.160 --> 0:04:45.880 that fight it off. Next time you run into that 0:04:45.920 --> 0:04:50.400 same virus, your immune system is ready for battle. The 0:04:50.480 --> 0:04:55.440 thing is, that's not always how it works. Immunity is 0:04:55.480 --> 0:04:59.479 actually a spectrum. There are viruses like the measles that 0:04:59.520 --> 0:05:03.680 you can for never worry about again. On the other 0:05:03.839 --> 0:05:07.520 end of that spectrum, there's HIV, in which the antibodies 0:05:07.560 --> 0:05:10.400 you developed just act as a sort of marker rather 0:05:10.480 --> 0:05:15.760 than actually protecting you from anything. Stars cove to. The 0:05:15.839 --> 0:05:20.120 virus that causes COVID nineteen is still pretty much a mystery. 0:05:20.360 --> 0:05:22.599 We just don't know that much about how the body's 0:05:22.640 --> 0:05:27.559 immune system responds to it. Recently, Anthony Fauci, the leading 0:05:27.600 --> 0:05:30.559 infectious disease expert in the country, was on Good Morning 0:05:30.560 --> 0:05:34.880 America talking about exactly this. We do not know exactly 0:05:35.360 --> 0:05:38.040 what an anybody tie to means. I mean, there's an assumption, 0:05:38.839 --> 0:05:41.960 a reasonable assumption, that when you have an anybody that 0:05:42.000 --> 0:05:45.400 you will protect it against reinfection. But that has not 0:05:45.520 --> 0:05:49.799 been proven for this particular virus. It's true for other viruses. 0:05:50.080 --> 0:05:52.400 I think it's a reasonable assumption. So you wouldn't say 0:05:52.680 --> 0:05:55.720 you know that's an absurd idea. It isn't. I mean, 0:05:55.760 --> 0:05:58.480 it happens with other viruses, But we don't know how 0:05:58.560 --> 0:06:02.599 long that pt action, if it exists last is it 0:06:02.720 --> 0:06:11.800 one month, three months, six months, a year? So that's 0:06:11.800 --> 0:06:14.120 a lot to unpack Foult. She was talking about a 0:06:14.120 --> 0:06:18.760 few different things. There are two key questions that scientists 0:06:18.760 --> 0:06:21.599 are trying to answer when it comes to antibodies and 0:06:21.680 --> 0:06:25.640 the new coronavirus. How long did antibodies two stars covie 0:06:25.720 --> 0:06:28.440 to remain in the body and for how long do 0:06:28.560 --> 0:06:33.520 they actually prevent you from catching it again if at all. Ideally, 0:06:33.800 --> 0:06:37.600 what you want is lifelong immunity, something you can give 0:06:37.640 --> 0:06:41.960 people a vaccine for that lasts forever. But early evidence 0:06:41.960 --> 0:06:44.720 suggests that stars CoV two is going to be a 0:06:44.800 --> 0:06:49.240 bit more complicated than that. The new coronavirus is a 0:06:49.279 --> 0:06:52.520 member of the same group of viruses as Stars and merrs, 0:06:52.920 --> 0:06:56.560 as well as the seasonal coronaviruses that cause the common cold. 0:06:58.120 --> 0:07:01.360 They're named coronavirus is has The proteins that the virus 0:07:01.400 --> 0:07:03.880 has used to attach to cells in a host body 0:07:04.040 --> 0:07:09.320 are kind of spiky, like a crown. Here's Harvard scientist 0:07:09.400 --> 0:07:13.520 David wall. To explain this a little bit, coronavirus is 0:07:13.560 --> 0:07:17.480 similar to the one that we're dealing with now COVID nineteen, 0:07:18.160 --> 0:07:23.200 such as the first Stars epidemic and the Mirrors infections 0:07:23.200 --> 0:07:26.480 that occurred primarily in the Middle East a few years ago. 0:07:27.000 --> 0:07:33.680 Those antibody responses were transient. That is, individuals who were 0:07:33.760 --> 0:07:38.760 infected lost their immunity after somewhere between two months and 0:07:38.800 --> 0:07:43.160 eighteen months, so that most individuals who were affected are 0:07:43.200 --> 0:07:48.040 no longer protected against those viruses. Stars and MERS are. 0:07:48.040 --> 0:07:51.440 The virus is most closely related to STARS Kobe two, 0:07:51.840 --> 0:07:54.840 and a few studies have shown that after a few years, 0:07:54.920 --> 0:07:59.720 antibodies to the virus disappear, meaning there's potential to get reinfected. 0:08:00.880 --> 0:08:04.200 Studies of both of those viruses also haven't actually shown 0:08:04.360 --> 0:08:09.440 the antibodies prevent reinfection. To further complicate things, not only 0:08:09.480 --> 0:08:13.640 are antibodies potentially time limited, but not all antibodies are 0:08:13.640 --> 0:08:17.400 actually capable of preventing infection in the first place. Some 0:08:17.680 --> 0:08:20.680 can recognize the virus but not actually latch onto it 0:08:20.800 --> 0:08:23.560 in order to fight it off. The antibodies you want 0:08:23.560 --> 0:08:27.880 are called neutralizing antibodies. Antibodies that cannot just recognize the 0:08:27.960 --> 0:08:31.120 virus but kill it. There's also the chance that the 0:08:31.200 --> 0:08:34.360 virus could mutate enough the antibodies you have no longer 0:08:34.480 --> 0:08:38.360 protect against it. One study from the nineties showed that 0:08:38.440 --> 0:08:42.880 was possible with a seasonal coronavirus. The present thinking is 0:08:42.920 --> 0:08:47.320 that people who have been exposed develop some immunity to 0:08:47.480 --> 0:08:50.440 the virus, but we do not know how long that 0:08:50.559 --> 0:08:54.600 persists and whether that is even going to be protective 0:08:54.800 --> 0:08:57.960 over a long period of time. The reason all of 0:08:58.000 --> 0:09:00.880 this matters is that understanding whether people are immune to 0:09:00.920 --> 0:09:04.000 the virus will help make decisions about how and when 0:09:04.080 --> 0:09:08.839 to lift restrictions like shelter and place. Test that measure 0:09:08.880 --> 0:09:11.400 antibodies to the virus have been sold as a major 0:09:11.559 --> 0:09:14.240 part of efforts to restart the economy and get people 0:09:14.280 --> 0:09:17.520 back to work. New York State has approved an antibody test. 0:09:17.720 --> 0:09:20.720 Fauci himself at one point even suggested that certificates of 0:09:20.760 --> 0:09:25.720 immunity might be required for returning workers. But that only 0:09:25.720 --> 0:09:29.560 works if we know the antibodies actually fend off the virus. 0:09:30.080 --> 0:09:36.560 Here's Fauci again. So the assumption that with the tests 0:09:36.600 --> 0:09:40.080 that are out there, if you haven't anybody positivity, you're 0:09:40.120 --> 0:09:43.640 good to go. Unless that test has been validated and 0:09:43.720 --> 0:09:47.760 you can show there's a correlation between anybody and protection, 0:09:48.240 --> 0:09:51.480 it is an assumption to say that this is something 0:09:51.480 --> 0:09:53.640 that we can work with. We still have a way 0:09:53.640 --> 0:10:02.840 to go with them. The good news there is some 0:10:03.080 --> 0:10:06.280 early evidence that antibodies means some sort of protection against 0:10:06.280 --> 0:10:11.040 COVID nineteen. For example, inexperimental treatments where critical patients are 0:10:11.040 --> 0:10:14.000 given blood plasma transfusions from people who have recovered from 0:10:14.000 --> 0:10:20.120 the illness. It seems to make a difference. But there's 0:10:20.120 --> 0:10:22.199 still a lot of work that needs to be done 0:10:22.360 --> 0:10:25.840 before we can answer these questions and develop vaccines and 0:10:25.920 --> 0:10:40.960 reopen the economy. That was Kristin V. Brown and that's 0:10:40.960 --> 0:10:44.040 our show today. For coverage of the outbreak from one 0:10:44.440 --> 0:10:48.400 and twenty bureaus around the world, visit Bloomberg dot com 0:10:48.440 --> 0:10:53.040 slash coronavirus and if you like the show, please leave 0:10:53.120 --> 0:10:57.000 us a review and a rating on Apple Podcasts or Spotify. 0:10:58.080 --> 0:11:00.680 It's the best way to help more listen nurds find 0:11:00.679 --> 0:11:05.120 our global reporting. The Prognosis Daily edition is hosted by 0:11:05.160 --> 0:11:09.680 me Laura Carlson. The show is produced by me Tophor Foreheads, 0:11:09.960 --> 0:11:15.679 Jordan Gaspoure and Magnus Henriksen. Today's main story was reported 0:11:15.679 --> 0:11:21.079 by Kristin V. Brown. Original music by Leo sidron Our. 0:11:21.200 --> 0:11:26.160 Editors are Francesco Levi and Rick Shine. Francesco Levi is 0:11:26.200 --> 0:11:29.600 Bloomberg's head of podcasts. Thanks for listening.