Speaker 1: It's Monday, June one. I'm Oscar Ramirez from the Daily
Speaker 1: Dive podcast in Los Angeles, and this is your daily
Speaker 1: coronavirus update. Will unrest continues across the country. Concerns about
Speaker 1: the coronavirus pandemics still remain. We are still waiting for
Speaker 1: a treatment or vaccine, but there's also some uncertainty to
Speaker 1: immunity for those that have had the disease and recovered.
Speaker 1: We still don't know for how long someone might be
Speaker 1: protected from COVID nineteen after they have gotten it and
Speaker 1: in your body. It's not just anybodies that are fighting
Speaker 1: the virus. B cells and T cells also helped fight
Speaker 1: illnesses after anybody's have disappeared. Katherine Wu, science reporter at
Speaker 1: Smithsonian Magazine, joins us for why immunity that the coronavirus
Speaker 1: is so complicated. Thanks for joining us, Katherine, Thank you
Speaker 1: for inviting me. It's great to be here. I wanted
Speaker 1: to talk about the coronavirus COVID nineteen. We've been battling
Speaker 1: this for some months now, and one of the things
Speaker 1: that we haven't had a chance to really wrap our
Speaker 1: head around is immunity from the virus. Once you get it,
Speaker 1: Are you even completely immune from it? And there's a
Speaker 1: lot of stuff that goes into it. It's pretty complicated
Speaker 1: in the way it works in our bodies. So Catherine
Speaker 1: helped us out a little bit to understand why immunity
Speaker 1: to this has been so complicated so far. Yeah, I mean,
Speaker 1: I'm really glad that you're looking into this, because it's
Speaker 1: best a complicated question, and I think during such a
Speaker 1: chaotic time when there are lives at stakes, people really
Speaker 1: want clear cut answers, and I as the report that
Speaker 1: we don't have a lot of those right now. I
Speaker 1: think the most important takeaway at this point is that
Speaker 1: even though we have tests and a lot of people
Speaker 1: working very hard on this disease and how to fight it,
Speaker 1: we don't really have clear cut answers on whether or
Speaker 1: not people are going to be protected from getting infective
Speaker 1: with the virus a second time, even if they've recovered
Speaker 1: from about a public night scene. The way that I
Speaker 1: sort of look at this is a lot of people
Speaker 1: by now have heard of antibody tests, either of the
Speaker 1: tests that searching your blood for those immune molecules that
Speaker 1: your body makes in response to a pathogen that's trying
Speaker 1: to infect you kind of like dusting for fingerprints after
Speaker 1: a crime has occurred at a crime scene. It's evidence
Speaker 1: that something has been in your body. But that's a
Speaker 1: very past focused book at the disease. It doesn't tell
Speaker 1: you a whole lot about the speaker. Yeah, And one
Speaker 1: of the things, whether anybody's, that I didn't really know
Speaker 1: about too much, is that they have a kind of
Speaker 1: a short lifespan, and they disappear from your blood after
Speaker 1: a few weeks or months, depending on how strong your
Speaker 1: immune system response was. And it's really these other cells
Speaker 1: in your body that kind of remember what those antibodies were.
Speaker 1: So if the same pathogen comes back into your body
Speaker 1: obviously we're talking about COVID nineteen, if you get infected
Speaker 1: again or something, these other cells are the ones that
Speaker 1: remanufacture those antibodies. So there's a lot of other stuff
Speaker 1: involved in really making your body continue to fight these diseases. Yeah, exactly,
Speaker 1: that's a really pretty point, So I thinks drive home
Speaker 1: so specifically about the antibodies, You're exactly right. Those are
Speaker 1: molecules made by the body by a population called B cells,
Speaker 1: And it's sort of the difference between you know that
Speaker 1: old addage like you know, give them person a fish
Speaker 1: and they eat for a day, keeps them how to
Speaker 1: fish and they can eat for life. Those antibodies are
Speaker 1: pretty temporary, but what is really important are those B cells,
Speaker 1: which remember how to make those antibodies against the virus itself.
Speaker 1: And so what you really want is those B cells
Speaker 1: to stick out around some then will kind of go
Speaker 1: dormant after you've recovered from an infesttion and then their
Speaker 1: ideal circumstances so hang around in your body. So then
Speaker 1: we'll keep dividing or just hang out for a really
Speaker 1: long time in the bone marrow. And then if that
Speaker 1: pathogen kind of comes to invade your body again, they
Speaker 1: will recognize that the pathogen hast come back and manifest
Speaker 1: those antibodies for a second time, and the response will
Speaker 1: be even stronger and faster than before, possibly so fast
Speaker 1: and so strong that you may not even experience symptoms
Speaker 1: the second time. Yeah, And of course that's what everybody
Speaker 1: would hope for that they can have. So there's also
Speaker 1: there's B cells, and then there's T cells T as
Speaker 1: in TOM, and some of these cells also help in
Speaker 1: this same thing, manufacturing and helping fight the viruses once
Speaker 1: they come back. So B cells and T cells are
Speaker 1: kind of two prongs of what's called the adaptive I
Speaker 1: mean response, and that's the kind of slow wave that
Speaker 1: kicks in roughly a week into infection, depending on what
Speaker 1: pathogen we're really talking about. And T cells serve kind
Speaker 1: of a different function, Like I guess I see B
Speaker 1: cells as weapons factories they're making antibodies, whereas T cells
Speaker 1: can actually accomplish a lot on their own. T cells
Speaker 1: can either help B cells make antibodies, so they're sort
Speaker 1: of supporting the antibody factories as they're churning these really
Speaker 1: important disease fighting molecules out, or T cells can sort
Speaker 1: of fight their own war. They can actually identify your
Speaker 1: own cells like the rest of the cells in your body,
Speaker 1: like the cells that might line your airway, recognize the
Speaker 1: ones that have been infested with a virus, and actually
Speaker 1: send the signals to tell them to self destruct, because
Speaker 1: at that point they figure that sells the lost cause
Speaker 1: it's been effect of the pathogen. The best way to
Speaker 1: deal with the situation is to make that cell get
Speaker 1: rid of itself, and that will also theoretically destroy the
Speaker 1: viruses inside of it. Do we have any information yet
Speaker 1: I know we're very uncertain on this whole thing. I
Speaker 1: had been reading about study in South Korea that basically
Speaker 1: said some people that have retested positive again for coronavirus
Speaker 1: weren't shedding active particles of the virus. In other words,
Speaker 1: they were clearing all those people. If you had COVID
Speaker 1: nineteen and you recovered, you were no longer infectious to
Speaker 1: other people. So it kind of plays into this whole thing.
Speaker 1: But has there been any other studies going around. That's
Speaker 1: the only one that I've seen. Really, I'm glad you
Speaker 1: brought up that bit of news because I think they
Speaker 1: have a little bit of nuance there that's may be
Speaker 1: important to get into. I feel like there were a
Speaker 1: few reports coming out in early days talking about reinfection,
Speaker 1: like people were testing positive, having symptoms, then recovering and
Speaker 1: testing negative. And in this case, I'm talking about the
Speaker 1: test that looks for the virus, not antibody. So this
Speaker 1: is a diagnostic test that can tell whether or not
Speaker 1: the viruses in your body, and probably active people were
Speaker 1: testing positive, than negative, then positive again, and people were
Speaker 1: wondering are people getting reinfected? Does that mean that these
Speaker 1: people aren't And the into the virus, and we're just
Speaker 1: doomed to get infected over and over again. I think
Speaker 1: a lot of experts have since come forward to say
Speaker 1: that these people probably we're fighting the virus. The virus
Speaker 1: sort of declined to very low, difficult to detect levels
Speaker 1: in their body, and the tests were missing the virus
Speaker 1: because it was so scarce in the body. And then
Speaker 1: after some time, maybe the immune system kind of relaxed
Speaker 1: and the virus maybe took the opportunity to sort of
Speaker 1: surge back to higher levels levels that were maybe triggering
Speaker 1: another bout of symptoms or making the virus detectable by
Speaker 1: these tests again. And so I think in that sense,
Speaker 1: it's really difficult to say exactly what was going on
Speaker 1: inside the body. But you know, that doesn't necessarily bad news.
Speaker 1: There are a lot of pathogens, including viruses, bacteria, parasites
Speaker 1: that can kind of linger in the body. But if
Speaker 1: we're able to detect this early, this won't necessarily be
Speaker 1: universal for everyone, and we can develop treatments that can
Speaker 1: either keep the virus at extremely low levels so that
Speaker 1: people aren't experiencing symptoms or are shedding the virus. That's
Speaker 1: kind of what happens with HIV and people can you know,
Speaker 1: live very long, healthy lives in that case, or you know,
Speaker 1: this will kind of inform when can we sort of
Speaker 1: target and treat the virus so that it doesn't establish
Speaker 1: maybe a population in the body that's going to be
Speaker 1: this long lasting. But I definitely don't want to give
Speaker 1: people the impression that this is the norm or that
Speaker 1: they're going to be stuck with this virus permanently, just
Speaker 1: that that could be the case for a subpopulation of people.
Speaker 1: There's still so much yet to be learned about the
Speaker 1: virus and how it lives within the body and all,
Speaker 1: and it's important for vaccine development and all that, so
Speaker 1: hopefully soon we can start understanding a little bit more.
Speaker 1: Catherine Wu, science reporter at Smithsonian Magazine, thank you very
Speaker 1: much for joining us. Thank you my Oscar Emiraz, and
Speaker 1: this has been your daily coronavirus update. Don't forget that.
Speaker 1: For today's big news stories, you can check me out
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