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Why scientists need to learn more about how COVID-19 behaves within a human body

How much do we know about COVID-19, the virus spreading misery across the globe? Dr. Siddhartha Mukherjee joins Jeffrey Brown to discuss understanding the dynamics of the virus within people it has infected, why some experience much more severe forms of illness than others, how we can limit asymptomatic transmission and the need to buy medical researchers time to develop treatments.

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  • Judy Woodruff:

    We have spent much time looking at how to cope with COVID-19, its impact and worldwide disruption.

    Tonight, we're going to try to understand a little more about what we're learning about the novel coronavirus itself and how it behaves.

    Jeffrey Brown has our conversation.

  • Jeffrey Brown:

    And for that, I'm joined by Dr. Siddhartha Mukherjee. He's an oncologist, cancer researcher and Pulitzer Prize-winning author. And he's just written a new article on COVID-19 for "The New Yorker."

    Welcome. Thank you for joining us.

    You wrote that, so far, we have been measuring the spread of the virus across people. We need to start measuring within people.

    Can you explain what you mean by that and why it's important?

  • Siddhartha Mukherjee:

    Well, during a pandemic like this, the first thing that we want to do is to track how fast it's moving across populations, and that's what I mean by measuring virus across people.

    That's really an on/off, 0/1, plus/minus, kind of assessment. Are you infected? Are you not infected? Are you symptomatic? Are you not symptomatic?

    But then there's a second phase of the pandemic, when you need to begin to understand the dynamics of the virus within people, which is, how much virus were you exposed to? How much virus does that exposure lead to an infection? And are you immune? Once you get the virus, do you get immunity to the virus?

    These are things that help us understand the dynamics of the epidemic as it moves across a population.

  • Jeffrey Brown:

    Well, so there is still so much mystery about what happens when it attacks one person, as opposed to another.

    What have we learned so far that helps us respond?

  • Siddhartha Mukherjee:

    Well, there are several things we have learned.

    First of all, we have learned that a — that the virus is mainly transmitted through respiratory droplets or so-called fomites. That's the main mode of transmission.

    The second thing that we have learned, or trying to learn, we're in the middle of learning, is that there are several people who are asymptomatic who may be shedding virus. That's a very, very important idea. That is to say that there may be a child or someone who doesn't have any symptoms, no fever, no diarrhea, no respiratory symptoms, but nonetheless is shedding the virus.

    We need to identify those people and isolate and potentially quarantine them, so that they don't keep spreading the virus.

    The third thing that we are learning, which we haven't learned for sure, is that there seems to be — if you do the right kind of test, there seems to be a way to predict whether you're going to have very severe disease vs. a more mild form of the disease.

    And that helps because that will help us triage patient to those who are either going to be sick and therefore require urgent attention vs. those who may become less sick and may be able to be managed more conservatively too.

  • Jeffrey Brown:

    Do these individual responses have implications for current discussions about, for example, wearing masks, whether all of us should wear masks?

  • Siddhartha Mukherjee:

    Well, so, absolutely they have an enormous role in this.

    I think the general conclusion, although we don't know this empirically, what one would logically conclude from this information is that health care workers need full masks. And by that, I mean they need the really protective masks. Those are N95 masks.

    If you are not a health care worker and you happen to have an N95 mask, please do a social service and donate it to a health care worker. So that's the first thing that we need that we know.

    The second thing that we know is that, for most respiratory viruses, if the viral load isn't the kind of viral load that a health care worker is receiving, there is a mountain of evidence that suggests that a simple surgical mask is essential.

    It works — such a mask works income in conjunction with hand hygiene and social distancing. These are not — this is not to say you should stop practicing hand hygiene and social distancing. But it is to say that, if you are an essential worker, and if you're being asked to work during this time, I do think that wearing a simple surgical mask would be effective and would be helpful in trickling down the amount of infection.

    If you happen to have an N95 respirator, please consider donating it to a health care worker who desperately needs one.

  • Jeffrey Brown:

    You know, you wrote in your article that every virus has its own personality.

    And I wonder, how different is COVID-19? And how confident are you that we will come to understand it enough to help in time?

  • Siddhartha Mukherjee:

    I'm very confident that we will understand it in time.

    COVID-19 is a unique virus, but it belongs to a family of viruses, including SARS and MERS and other coronaviruses that we have been dealing with for a very long time. It is not something peculiar and mysterious that has suddenly emerged.

    We know this family of viruses well enough. We are in the midst — as a medical community, in the midst of launching an extraordinary phase of drug trials to treat the sickest patients. So, if there's one message, I would say, with regard to the virus is that you need the population, the public, everyone, needs to buy us time.

    We need time to get these trials launched. We need time to get — to ensure that they are done correctly, so that when the full wave of the sickest patients hits us, we will be prepared for them.

  • Jeffrey Brown:

    Before we go, I want to ask you.

    There's a new documentary about to come out on PBS called "The Gene." It's based on your book of a few years ago. And it makes us all, I think, wonder about the analogy — or the connection, rather, between that history that you're documenting about the genetic code and what's going on today with this virus, how we're trying to understand it, how we're trying to respond.

  • Siddhartha Mukherjee:

    Virtually every technology that we're using to quantify, understand and deepen our understanding of COVID-19 relies on genetics.

    There is — you know, the word viral load really is a quantification of the amount of virus in the body using genetic techniques. So — and also the production of drugs, such as antibodies, depends on recombinant DNA technology.

    To understand how the last 100 years of genetic medicine and genetic technologies have impacted our understanding of infectious diseases and pandemics such as COVID, I would encourage you to watch it.

  • Jeffrey Brown:

    All right.

    So, you and I will talk a little bit more about the documentary, and we will put that online in the coming days.

    For now, Dr. Siddhartha Mukherjee, thank you very much.

  • Siddhartha Mukherjee:

    My pleasure. Thank you so much. Hope you stay well.

  • Jeffrey Brown:

    Thank you. You, too.

  • Judy Woodruff:

    And you can watch "The Gene" on your PBS station starting next week. It airs in two parts on April 7 and 14.

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