Today, Explained - The immunity test

Episode Date: April 6, 2020

A vaccine will take a while, but Vox’s Umair Irfan says the global effort to test for immunity and treat Covid-19 is well underway. (An earlier version of this episode misidentified hydroxychloroquine as an active ingredient in aquarium cleaner. That's chloroquine phosphate.) (Transcript here.) Learn more about your ad choices. Visit podcastchoices.com/adchoices

It's Monday, April 6th, 2020, and a tiger at the Bronx Zoo has the rona. I'm Sean Ramos-Furham, and this is your coronavirus update from Today Explained. The tiger's name is Nadia. She's a four-year-old Malayan tiger, and she's got a dry cough. She evidently got it from a Bronx Zoo employee. The good news is she's expected to recover soon. In bad news, the country's Surgeon General Jerome Adams said the nation should prepare for the hardest and saddest week of most Americans' lives. He said it's about to feel a lot like Pearl Harbor or 9-11.

He called on all Americans to do their part to flatten the curve. New York's Governor Andrew Cuomo says they might be flattening the curve there. The state's daily death toll has dropped slightly since a Friday peak with 630 lives lost. The governor pointed out that the drop could be a blip. China did New York a solid this weekend and donated 1,000 ventilators. That news came just after President Trump said he was unwilling to get New York all the ventilators it requested.

But the president and his son-in-law did help New York City get some masks. The city recently received something like 600,000 N95 masks from the federal government. Elsewhere, Boris Johnson has been hospitalized due to complications from COVID-19. The BBC is reporting he's in intensive care. As of publishing, he's still in charge of the government. Meanwhile, the almost 94-year-old Queen of England gave a rare televised address over the weekend, saying, We should take comfort that while we may have more still to endure,

better days will return. We will be with our friends again. We will be with our families again. We will meet again. Two giant pandas in Ocean Park, Hong Kong met again this morning. Ying Ying and Lele mated naturally for the first time in 10 years. The chance of pregnancy is apparently better when mating happens naturally. Maybe they just needed the humans to stay six feet away.

You can get closer digitally to Today Explained, though. We're on Twitter at today underscore explained or at Ramas for them. You can call us and leave a message to the numbers 202-688-4944. And there's always email todayexplained at vox.com. Bet MGM, authorized gaming partner of the NBA, has your back all season long. From tip-off to the final buzzer,

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or someone close to you, please contact Connex Ontario at 1-866-531-2600 to speak to an advisor free of charge. BetMGM operates pursuant to an operating agreement with iGaming Ontario. Everyone wants to know when this ends. June, August, Halloween. No one seems to know. It hinges on a vaccine, right? But a vaccine is still a ways away.

Some say the pandemic will have peaked and even declined before we get a vaccine. In the meantime, we're going to get serious about something called serological testing. And it's okay if you have no idea what that is, because Umair Irfan has been writing about it for Vox. Well, a serological test tests the blood serum, and it looks for antibodies or proteins that are made specifically to target the virus by our own immune systems. So it's like testing for immunity. That's right. And this is happening all over the world right now? In other countries, they've been using these kinds of serological tests for several months

throughout this pandemic. But the Food and Drug Administration just recently approved the first serological test that can be used for diagnosing COVID-19. We have provided regulatory flexibility to other laboratories and other producers so that they can develop their own tests. The concern, though, is that looking for antibodies is not a surefire way of identifying the virus. It can take several days for an infection to start generating antibodies by the immune system. So there's the concern that early on in an infection, this test

won't pick up the virus. That said, given that we have such a huge testing shortage, public health officials need all the help they can get. And this might be a step towards that. Okay, so these are not the tests for COVID-19 that we keep hearing about, the tests that we don't have enough of. This is a totally different kind of test. That's right. The main test we're using right now to look for active infections looks for the virus's genome. It looks for the RNA molecules that the virus uses to replicate itself. And right now that test shows whether or not you have an active infection, but it doesn't really give you a sense of who has had the virus or who may have fought it off and has had the virus clear their system. And that's where serological testing comes in. How does it work exactly? So it's a blood test. You give your blood, then what happens?

There are different kinds of techniques, but some of the techniques that are approved are basically you put a few drops of blood with some reagents and diluting solution into a cartridge and essentially it just runs through the cartridge and you see lines pop up showing whether or not you have the antibodies to the virus. It looks kind of like a pregnancy test. And if you see a positive line, it basically shows that you have antibodies to the virus. Now, it doesn't mean that you fought off the virus. You could still be infected and produce antibodies, or you could have the antibodies without the virus. But it's a sign that the virus has been present in your system.

And then you'll know whether or not you're immune? Well, antibodies are a key step towards generating immunity. And so it's likely that having these antibodies means that you're immune. But scientists are still trying to figure that out. They're looking at basically our experience with past coronaviruses like SARS and MERS, and many of them do believe that there is some immunity that can be gained if you survive a COVID-19 infection.

But I feel really confident that if this virus acts like every other virus that we know, once you get infected, get better, clear the virus, that you'll have immunity that will protect you against reinfection. But right now, they don't know how long that immunity will last and how robust that immunity is. So it's a little early to start telling people who have positive antibody tests to go right back to work. That said, in emergency situations in places like hospitals where there's a shortage of health workers that are urgently

needed, you know, some people that were infected that might be needed back in action, they could get this test and potentially, you know, swallow the risks and get back to work. And that's one place where a test like this could be very useful. maybe had COVID-19 in December before it was even called COVID-19? Because we've heard time and again, people saying, I have had these exact same symptoms around the holidays, around the new year, and I was flat on my back and had no idea what was going on. I thought it was the flu, but it wasn't the flu. Will this help us clear any of that up? Absolutely. That's one of the main functions of a test like this. It lets you kind of look back in the past or get like a picture of how the virus has been spreading through

a population. One of the things that we've noticed about this virus is that people can spread it before they show symptoms, and many of the infected people don't show symptoms at all. And we really don't have a good sense of who those people are or how many there are unless we do these kinds of serological tests to see whether their bodies have mounted an immune response to it. This is a key test that can answer those kinds of questions and help us get a better understanding of the virus and also understand things like symptoms because the symptoms can vary quite a bit from person to person.

There are some people get very seriously ill. People have been hospitalized. People have died from this. And there are people who just barely noticed they were infected at all. So how do you know you've been sick or not? How can you tell you need a test? That's a question we can answer more readily if we have this kind of information by looking back at past cases and past infections.

And you said the FDA has just started executing these serology tests. How long is this process going to take? Well, there have been doctors across the U.S. who have been using serology tests, how long is this process going to take? Well, there have been doctors across the U.S. who have been using serology tests sort of off the books for a while now. On COVID-19? On COVID-19, yes. Because, you know, they were so desperate for tests that they were willing to use these kinds of things as one element to try to diagnose the infection, if not the sole element. The fact that the FDA approved this, though, for diagnosis shows that there's still an urgent demand and that they think that this test is robust enough, even with all the caveats, that it is something that we can use to diagnose

the infection. And there are a bunch of other companies that are also seeking authorization for using these kinds of tests to diagnose the infection, then potentially later in the future to start screening the population at large to trace the history of this virus in our population. Hmm. But we're not the only ones doing this. Is it plausible that another country, another organization makes a ton of progress and then shares that information with the FDA, with the United States, and, you know, there's some sort of greater global effort? Well, other countries have already been developing and using these tests for some time, you know, Singapore, South Korea, and in China, they've been deployed quite widely. Germany has broached the idea of actually certifying people who have positive serology tests, basically showing that they have the antibodies to the virus, potentially as a way to show that these are people that are okay to return to work.

The United Kingdom has also talked about creating a passport for potentially people who have survived the infection. You know, this is not all that different from like an immunization record that you need to show to attend school or to enter certain countries, for instance. And it makes sense that, you know, you could do something like this for potential COVID infections or for people who have the immunity to it. If you're doing blanket testing, if you're testing hundreds of thousands of people and doing things like contact tracing or looking at where people have been moving or tracing location histories

from cell phones in tandem with all these other things, then you get a much more robust picture. The problem we've been having in the US is we've been struggling to get any kind of testing done at all at any level of scale. And so doctors and hospitals have been rationing these tests mainly for people who have been admitted to emergency rooms and ICUs or for medical personnel who may have been exposed. We can't really do the widespread contact tracing unless we have much more testing capabilities. Just more great news. Yeah, it's been a pretty frustrating experience just to get a handle on the number of cases in the United States.

That said, the U.S. is also making a lot of progress on treating the virus and working its way toward a cure. And they actually had a bit of a head start when it came to this particular virus. More with Umair after the break. Support for Today Explained comes from Ramp. Ramp is the corporate card and spend management software designed to help you save time and put money back in your pocket. Ramp says they give finance teams unprecedented control and insight into company spend. With Ramp, you're able to issue cards to every employee with limits and restrictions and automate expense reporting so you can stop wasting time at the end of every month. And now you can get $250 when you join Ramp. You can go to ramp.com slash explained, ramp.com. Ramp.com.

Cards issued by Sutton Bank. Member FDIC. Terms and conditions apply. Okay, Umair, we talked about serological testing and how it's going to help us better figure out who's immune and maybe even why, but then you broke the bad news that we don't have a ton of testing capability there either. What's up with treatment? Is there better news there? Right now, there's a sort of throw everything at the wall and see what sticks approach to this. There are so many people infected and everybody's kind of pulling out all the stops to see what can work. The one upshot here is that this novel coronavirus fits within a family of other coronaviruses that the world has had some experience treating. And so there's been a little

bit of a head start here in terms of trying to figure out what could potentially work. We have experience with illnesses like SARS and MERS, kind of seeing what worked there and what didn't. And that could potentially, you know, smooth the path toward getting a more effective treatment out to the world sooner. How about here in the United States? Is the United States developing anything independent of the rest of the world? Well, most of these efforts are international. They're working across borders. The companies that are developing it are multinational companies. But yes, there are a number of clinical trials undergoing here in the United States. One of the more notable ones is a drug called remdesivir. This is developed by a company called Gilead. Remdesivir. The way it

works is that it interferes with the way the virus replicates itself. And it interferes with the virus, but not with any human cells. So it has a very targeted effect. And this was a drug that was in development to deal with previous coronaviruses or previous infections. And so there was already a little bit of knowledge developed, but now they're pressing a little bit further, pushing it through trials to see whether it would be effective against this new virus. What about the one that the president keeps hawking in press conferences? What was that one called again? Hydroxychloroquine.

Yeah, it's like a malaria treatment? That's right. It's a powerful drug on malaria. And there are signs that it works on this, some very strong signs. And in the meantime, it's been around a long time. It also works very powerfully on lupus. Lupus. A drug like this is pretty tempting because, one, it's been around a long time. It also works very powerfully on lupus. Lupus.

A drug like this is pretty tempting because, one, it's already an approved therapy for other kinds of illnesses. It's an off-the-shelf drug. There are generics available. It's pretty cheap. The concern, though, is that it hasn't really been tested robustly against COVID-19. Some laboratory tests looking at cells in a petri dish showed that it could be effective at preventing the virus from entering cells. But the human trials have been much more mixed.

There was a study that was done in France where researchers were quite optimistic, and they said that the results were pretty promising. But that particular study was not a randomized trial, and the doctor who was running it was Notorious Crank. Notorious Crank. Some follow-up studies from research groups in China and another research group in France found it was really hard to distinguish whether this was actually making a difference for people who are sick. And there are some serious downsides to this drug, too. Like, this has some pretty serious side effects. You know. It can cause nausea, vomiting, and

headaches. And some people with heart conditions, it can cause some serious heart problems, and it can cause some neurological symptoms as well. One of the concerns, though, is that since the president has been promoting this, this drug has been flying off the shelves in pharmacies. There are now shortages for people who do need this drug for illnesses that are actually conditioned for this. Patients with lupus and patients with rheumatoid arthritis have had a hard time filling their own prescriptions because other people are trying to get prescriptions for hydroxychloroquine to prevent COVID-19. Is there anything other than remdesivir and hydroxychloroquine that we should be thinking about?

Well, doctors are also looking at other kinds of drugs that have been approved to treat other illnesses. So some researchers are experimenting with drugs that were used to treat HIV, for instance, those antivirals. But the trials so far have been also pretty mixed. There's also a treatment that's kind of related to the serology testing that we were talking about earlier. The idea is you can harvest antibodies from somebody who has recovered from the virus and use it to treat somebody who is sick, or even potentially give it to somebody to prevent them from getting sick, sort of as like a prophylactic. This blood plasma transfer treatment is something that's actually being used in extreme emergency

scenarios, but researchers are also investigating whether this could be used more broadly as a therapy once we can identify people who have had the virus and have built up the antibodies to it. The drugs and treatments we've talked about so far, they fit broadly into the category of antivirals. These are drugs and treatments that look at the virus directly and try to eliminate the threat that way. But then there are more generic treatments as well that we can use. And these are mainly immune system boosters. These

are the drugs and other kinds of pharmaceuticals that can boost our body's own natural defenses to the virus. What are we talking about, like orange juice? No, there's more like drugs like interferons. Interferons. These are signaling proteins that your body uses to indicate that there's an infection. And when your body detects this, it ramps up its immune response and it also makes cells harder to infect. The downside is that when you're using these kinds of immune system boosters, it's kind of easy to tip the body to overreact. Once your body's immune system gets ramped up, then you can have these other side effects like inflammation and fever, and it can actually end up causing

more damage to the body than the virus itself. And that's why you have to have a very careful calibration of these kinds of treatments. How much do we know so far about, you know, how well these antivirals and immune system boosters can help with treating COVID-19 and how much is yet to be determined? I mean, there's some anecdotal evidence that shows that certain combinations can be effective. But right now we're in a situation where we have an urgent public health need. And so there's a lot of emergency uses of this, but also an urgent need to do the research. And so researchers and doctors are trying to balance this, like the need to do a careful clinical controlled trial over several months versus having a patient in your ICU right

now who needs treatment. And that's kind of making it making a little bit difficult to answer some of these fundamental research questions. So this is sort of a trial by fire. We're actually seeing these real world uses of these drugs of doctors experimenting in their own clinics trying to figure out what could potentially work. And it will just take some time to see, you know, what actually pans out as an effective treatment. There was sort of an expectation or sort of this idea that this kind of thing couldn't happen here,

or if it could, it was not something that people realized that they needed to plan for. And now we have a better sense that this is possible, and there are tangible things that we could be doing to prepare for the next pandemic, from disease surveillance to having stockpiles of valuable medical

equipment that could be necessary. It is a learning experience. It's a hard lesson to learn. We could have been better, but hopefully we'll be in better shape for the next fight. But we're not out of this one yet. That's Umair Irfan. He's a science reporter at Vox. I'm Sean Ramos for him. This is Today Explained. Today Explained.