What We Know About Immunity

Vietnam confirmed its first death from the pandemic after a sudden cluster of cases emerged in the coastal city of Da Nang. For more than three months, the country appeared to have beaten back the virus. The death of a seventy year old man comes seven months after the nation recorded its first virus cases. The US government pledged its biggest investment yet in a vaccine. The Trump administration will provide as much as two point one billion dollars in

funding to vaccine partners Sunafi and Glaxo Smith Klein. The funding will support clinical trials and manufacturing, while allowing the US to secure one million doses of the shot if it's successful. The country has an option to receive an additional five hundred million doses. Longer term, the US has made billions of dollars and commitments to other experimental vaccines,

stoking concerns that some countries will be left behind. In England, more than four million people are being forced inside a large part of the country's northern region must comply with new tighter lockdown rules. Prime Minister Boris Johnson is rushing to tackle a new spike in cases, and his administration has forbidden residents in the Greater Manchester area and parts of East Lancashire and West Yorkshire from meeting indoors with members of other households. And now for today's main story.

In the race to study immunity to the virus, scientists first focused on antibodies, proteins that stick to and disable foreign invaders. That's because creating antibodies is the basis for most successful vaccines, so scientists are interested in learning who develops coronavirus antibodies, how long they stick around, and how

effective they are keeping people from getting infected again. But recent studies show there may be another weapon inside the human body that can rouse fresh antibodies soldiers long after the first have left the battlefield. Bloomberg Senior editor Jason Gale explains that T cells may be part of the key to blunting the coronavirus contagion. Let's start with the

antibody tests. That is, the possibility of an antibody test and showing that COVID antibodies fade quickly, but it's still not known if an antibody response will give future imming the antibodies. What does that mean? It means these are We've heard a lot about antibodies during the pandemic. Having specific antibodies against sarsko V two may prevent us from

catching the virus again. Some governments have suggested that they could serve as the basis for an immunity passport or risk free certificate that would enable people to travel or to return to work, assuming they are protected against reinfection. Problem is, there's currently no evidence that people who have recovered from COVID nineteen and to have antibodies are protected from a second infection. Scientists think they probably do, but

there's no proof. What's more, these antibodies don't appear to stick around lock, at least in people who have had a mold b out of the disease. Researchers in Los Angeles reported last week the rapid decay of anti Saskvy to antibodies and patients who had a mild case of COVID nineteen. They said their findings, published in the New England Journal of Medicine, suggested we should treat with caution.

The idea of immunity passports, as well as the durability of any vaccines that are produced, sounds kind of depressing, right, Well, maybe not when it comes to the immune system. Antibodies aren't a solo act. They're part of an entire orchestra of immune defenders that collectively make up our white blood cells. In the front row are the innate crew that respond

to a viral infection immediately and crudely. Then there's a more sophisticated bunch of adaptive immune responders that remember what games there fought in case they have to do battle with them again. Antibodies are one component of that adaptive immune response which immunization seeks to create without causing any disease, Which are the plants that are made from the cells and the ones that bind to a virus and neutralize.

This is Professor Alessandro setting He's a researcher at Lahoya Institute for Immunology in San Diego who has been studying the immune system for some forty five years. So if you have a high level of antibodies, you can neutralize the virus and avoid infection. Alessandro is interested in another component of the adaptive immune system, T cells. We recognize and destroy effect itselves. This is very important because when you have an infection, when a virus gets inside the cell,

it becomes an invisible for antibodies. We antibodies cannot get to it anymore. He's getting inside the cell. Some T cells directly kill these virally infected cells. Others play a support role, helping to regulate the immune system and remember microbial foes. Without a helper T cells, the antibody response is weak. Uh, it doesn't find very strongly, doesn't last

very long. Good news is that Alexandro and his colleagues have found that when people are infected with sisk V two, they amount a strong T cell response, and unexpectedly, he found some people who had never encountered sarask v two also had T cells that recognized the pandemic strain, which was odd since this is a completely new virus, and so this was very puzzling and we we looked at this data from right from left, from top from bottom,

and we really became convinced that this was absolutely real. Scientists in the Netherlands, UK, Germany and Singapore have reported the same thing, so it's really all over uh, different groups and different continents. So this was remarkable. So how do you explain how someone whose immune system has never seen this coronavirus before as some memory of it. And the most reasonable hypothesis, but we want to emphasize that this is an hypothesis at this point, is that this

is due to exposure to common called coronaviruses. There are four of them in circulation that caused the usual sore throat coffin running knows that we routinely experience in winter. Alessandre says Sis givy two is like a cousin of these less dangerous coronaviruses. This viruses evil cousin common called corona. So if you've seen this other viruses recently, maybe you

have a little bit of cross ripping. In other words, if you have encountered one of these cold causing coronavirus is recently, could it give you at least partial immunity. Alexandra says scientists are looking into this and are especially interested in studying people living on an island off the coast of Tuscany, where the incidents of COVID nineteen was very low, despite infected travelers from mainland Italy bringing it across.

That island was reported to have had the year before particularly bad common called the season, and so some of the people I talked there were speculated, well, maybe this has something to do, and I think that they were, uh, trying to set up and starting to look at this and more details. Alessandra says more research is needed to determine whether pre existing T cells that cross react with the Sasko V two virus may explain why some COVID patients are barely affected while others get very sick and

even die. Figuring out the role of cells in protecting against COVID it's pretty important since these white blood cells will be critical for achieving durable immune protection from many vaccines that are developed. The immune system is all about memory, and so is vaccination. You create a memory, so if maybe you have a pre existing little bit of memory response, your immune system has a head start compare to someone

that doesn't. We still don't know yet whether it's possible to develop vaccines that will stimulate potent antibodies against aus COVID two and prevent someone from getting COVID nineteen. According to Alessandro, the hope is that immunization will at least generate an immune response that lessens the severity of disease and the time it takes to recover from the infection, and this should go some way to blunt the pandemic. That was Jason Gale, and that's it for our show today.

For coverage of the outbreak from one hundred and twenty beers around the world, visit Bloomberg dot com Flash 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 listeners find our global reporting. The Prognosis Daily edition is produced by Tophor Foreheads, Jordan Gaspure, Magnus Henrickson, and Ni Laura Carlson. Today's main story was reported by Jason Gale. Original music by Leo Sedrin. Our

editors are Rick Shine and Francesca Levi. Francesca Levi is Bloomberg's head of podcasts. Thanks for listening.