Who's Really Immune?

for how long is still unclear. So who's really immune? But first, here's what happened today. The US recession has officially begun. After eleven years of record growth. The economy shrank at a four point eight percent annualized rate in the first quarter, with a coronavirus forcing businesses to close and consumers to stay home around the country. It's likely to be the deepest recession in at least eighty years. That's right, eighty years. The current quarter is expected to

be far worse. Bloomberg Economics projects an annualized contraction of a staggering thirty seven percent. The Trump administration has launched a project to fast track a coronavirus vaccine. The goal is to make enough doses for most Americans by the end of the year. The program, called Operation Warp Speed, will pull together private pharmaceutical companies, government agencies, and the military.

As part of the arrangement, taxpayers will shoulder much of the financial risk that vaccine candidates may fail instead of drug companies. There was good news from the pharmaceutical industry today which brought hope that the first effective treatment for coronavirus could be around the corner. Gilead Sciences said that remdesvie, their experimental drug to treat the virus, worked better than standard care in a clinical trial. The coronavirus outbreak is

at different stages around the world. In Europe, some countries are seeing fit to loosen restrictions on movement, others fear a second wave. France and Spain took cautious steps towards reopening, but in Germany new cases rose for the first time in three days as the government weighed removing more curbs. New York reported a fourth day of declining deaths, though new hospitalizations rose slightly. In other regions, the virus is taking an even more serious toll. Brazil is rising in

the ranking of most hit places by the coronavirus. It is now the country with the third largest number of deaths reported over the past twenty four hours, after the US and the UK, and now our main story. As states grapple with the question of when it will be safe to reopen businesses and relax social distancing, there's increasing urgency to better understand who's immune to COVID nineteen. Does having the virus and recovering from it mean you can't get it again, or at least that you can't be

reinfected for some time. The problem is no one yet has good answers to these questions. Here's Bloomberg reporter Kristin V. Brown with more on the science of coronavirus immunity. When I was a kid and I got the chicken pox, one of the things I remember my mom telling me is that I couldn't get the virus that caused the chicken pox again. She told me that I was immune. This, I think is common wisdom when it comes to viruses.

That is, after all, how vaccines work. You're exposed to a virus like polio or the measles, your immune system identifies that virus and figures out how to produce antibodies that fight it off. Next time you run into that same virus, your immune system is ready for battle. The thing is, that's not always how it works. Immunity is actually a spectrum. There are viruses like the measles that

you can for never worry about again. On the other end of that spectrum, there's HIV, in which the antibodies you developed just act as a sort of marker rather than actually protecting you from anything. Stars cove to. The virus that causes COVID nineteen is still pretty much a mystery. We just don't know that much about how the body's immune system responds to it. Recently, Anthony Fauci, the leading infectious disease expert in the country, was on Good Morning

America talking about exactly this. We do not know exactly what an anybody tie to means. I mean, there's an assumption, a reasonable assumption, that when you have an anybody that you will protect it against reinfection. But that has not been proven for this particular virus. It's true for other viruses. I think it's a reasonable assumption. So you wouldn't say

you know that's an absurd idea. It isn't. I mean, it happens with other viruses, But we don't know how long that pt action, if it exists last is it one month, three months, six months, a year? So that's a lot to unpack Foult. She was talking about a few different things. There are two key questions that scientists are trying to answer when it comes to antibodies and the new coronavirus. How long did antibodies two stars covie to remain in the body and for how long do

they actually prevent you from catching it again if at all. Ideally, what you want is lifelong immunity, something you can give people a vaccine for that lasts forever. But early evidence suggests that stars CoV two is going to be a bit more complicated than that. The new coronavirus is a member of the same group of viruses as Stars and merrs, as well as the seasonal coronaviruses that cause the common cold.

They're named coronavirus is has The proteins that the virus has used to attach to cells in a host body are kind of spiky, like a crown. Here's Harvard scientist David wall. To explain this a little bit, coronavirus is similar to the one that we're dealing with now COVID nineteen, such as the first Stars epidemic and the Mirrors infections that occurred primarily in the Middle East a few years ago.

Those antibody responses were transient. That is, individuals who were infected lost their immunity after somewhere between two months and eighteen months, so that most individuals who were affected are no longer protected against those viruses. Stars and MERS are. The virus is most closely related to STARS Kobe two, and a few studies have shown that after a few years, antibodies to the virus disappear, meaning there's potential to get reinfected.

Studies of both of those viruses also haven't actually shown the antibodies prevent reinfection. To further complicate things, not only are antibodies potentially time limited, but not all antibodies are actually capable of preventing infection in the first place. Some can recognize the virus but not actually latch onto it in order to fight it off. The antibodies you want are called neutralizing antibodies. Antibodies that cannot just recognize the

virus but kill it. There's also the chance that the virus could mutate enough the antibodies you have no longer protect against it. One study from the nineties showed that was possible with a seasonal coronavirus. The present thinking is that people who have been exposed develop some immunity to the virus, but we do not know how long that persists and whether that is even going to be protective

over a long period of time. The reason all of this matters is that understanding whether people are immune to the virus will help make decisions about how and when to lift restrictions like shelter and place. Test that measure antibodies to the virus have been sold as a major part of efforts to restart the economy and get people back to work. New York State has approved an antibody test. Fauci himself at one point even suggested that certificates of

immunity might be required for returning workers. But that only works if we know the antibodies actually fend off the virus. Here's Fauci again. So the assumption that with the tests that are out there, if you haven't anybody positivity, you're good to go. Unless that test has been validated and you can show there's a correlation between anybody and protection, it is an assumption to say that this is something that we can work with. We still have a way

to go with them. The good news there is some early evidence that antibodies means some sort of protection against COVID nineteen. For example, inexperimental treatments where critical patients are given blood plasma transfusions from people who have recovered from the illness. It seems to make a difference. But there's still a lot of work that needs to be done before we can answer these questions and develop vaccines and reopen the economy. That was Kristin V. Brown and that's

our show today. For coverage of the outbreak from one and twenty bureaus around the world, visit Bloomberg dot com slash coronavirus and if you like the show, please leave us a review and a rating on Apple Podcasts or Spotify. It's the best way to help more listen nurds find our global reporting. The Prognosis Daily edition is hosted by me Laura Carlson. The show is produced by me Tophor Foreheads, Jordan Gaspoure and Magnus Henriksen. Today's main story was reported

by Kristin V. Brown. Original music by Leo sidron Our. Editors are Francesco Levi and Rick Shine. Francesco Levi is Bloomberg's head of podcasts. Thanks for listening.